Zach has a very thin build and very pale skin; he is barely taller than Chris. He has black, shiny hair and green eyes, sporting a small goatee. He typically wears a black turtleneck sweater, gray slacks, and black pointed shoes. In winter climates, Zach takes to wearing a black trenchcoat tied at the waist along with gray gloves, slacks, short black heels and a gray turtleneck sweater underneath. His head is triangular in shape.
Zach is extremely arrogant, stubborn, and self-centered; he is also extremely narcissistic, often referring to himself as "the world's greatest mind" and programming his computers to call him “My Greatness,” in spite of the fact that his inventions often fail and Aviva's do not, and is even shown to have his own perfume (Polar Bears Don't Dance).
Zach is portrayed more comically than the other villains along with more slapstick moments; his screams are girlish, he constantly trips and falls, and he has to deal with the literal mindedness of his Zachbots. He is also somewhat sadistic, as he has been shown to resort to outright killing the Kratt brothers, such as when he lured them into an Arctic storm (Polar Bears Don't Dance), and attempted to drown them (Mystery of the Weird Looking Walrus and Creature Power Challenge).
He has an enormous ego, one that nearly rivals, if not outright surpasses, that of Donita Donata's. His arrogance is not unfounded, however, as he actually is a pretty good inventor, and he is also very wealthy. Despite this, he is also a coward. Due to his dislike of the Wild Kratts and their interferences, he usually refers to them as "Wild Rats".
Zach's plots typically involve collecting animals and turning them into robots, but not all of Zach's plots deal directly with animals, rather the animals simply just get in the way. These plots include stealing inventions and trying to win competitions by cheating.
He has professional robotics and engineering skills, with highly advanced tools and weaponry. His inventions are able to display holograms, laser-like projections, hovering capabilities, and/or being able to camouflage. He has an army of robot minions known as "Zachbots." He makes his robots do the dirty work, while he thinks up the plans.
Due to his immense wealth, Zach possesses various means of transportation, moreso than the other villains. His primary means of travel are a V-shaped jet, a large, gray cargo propeller plane, and a large, gray cargo jet. To travel by water, he either uses a steel plated yacht, or a gray submarine. All made to his designs, and they work pretty well.
In terms of physical strength, he is apparently weak as Gourmand once stated that he'd rather have Zach's arm strength than cook a farm turkey. In "Choose Your Swordfish, it’s shown that Zach has competent fencing skills, but he's not as good as Aviva.
- Zachbots (robotic henchmen)
- Mind-Control Skull Caps
- Mosquito Bots
- Disruptor Beam
- Bubble Bot
- Robotic Tree
- Hypnotic Eyes
- Invisibility Cloak
- Robotic Vest
- Cloud Camouflage
- Communication Jamming Net
- Robotic Mantis Arms
- His first appearance was in the episode "Aardvark Town" where he's in Africa on an animal collecting trip and he's wanting to build a swimming pool to cool off. When he hears the Kratt Brothers are looking for the best digger in Africa (which was the aardvark), Zach orders his Zachbots to search all the holes to find it. When they found her and several other animals living the holes she dug, he put mind-control armor on the aardvark and had the the other animals chained.
- In "Flight of the Draco", Donita Donata hired him and his Zachbots as security for her treetop fashion show.
- In "Platypus Cafe" Gourmand invited Zach and Donita to his restaurant, where he's found and captured Chris trying to save Plato's eggs. Later, Martin arrived to save the eggs and sent the villains floating down the river.
- In "Polar Bears Don't Dance" while Chris and Martin are following a mother polar bear and her cub (whom Martin names Poby), Zach is fascinated by how the cub looks like he's dancing. So he steals the cub along with a walrus calf and plans to them to dance for his audience at the opening of his new ice resort. But when the Kratt brothers catch up to him, the animal's mothers think they're in danger from each other and they engage in an intense fight which changes Zach's mind and decides to kidnap them instead and make them fight. So he tricks the brothers by luring them into an arctic storm. After the storm passes by, the Kratt brothers infiltrate his ice palace and free the mothers, forcing Zach to escape, swearing that the Kratt brothers will pay for their interference.
- In "Honey Seekers" Gourmand invites Zach once again to his restaurant for a cooked honey badger served with honey sauce. After Gourmand captures Chris and Aviva, Martin comes to the rescue with an army of honey badgers, who cause chaos in the kitchen and scare off the villains with their stink.
- In "Bass Class" Zach is seen relaxing on his yacht and gets annoyed by Gavin's shiny trophy so he tries to take it from him. Chris tells him that if he wants a trophy he'd have to win one of his own, so Zach announces a bass fishing contest in which he cheats at multiple times. First he attempts to use live bait, then he has his Zachbot observer scare off the bass around Gavin's boat, next he has his Zachbots to go and buy a bass at the fish market, but Chris knows he's lying so Zach throws him overboard. Then he goes off to the spawning grounds to catch the father bass, but that fails as well, so he ends up creates bass-like Zachbots which at first works, but then, their paint comes off revealing Zach’s trick, forcing him to retreat.
- In "Mystery of the Weird Looking Walrus" he steals the Arctic Pearl from amuseum and plans to give to Donita, only to end up losing it in the ocean. So he attaches a bunch of mind control helmets to a bunch of walruses and makes them slurp up dozens of clams to find it. And when the Kratt brothers use Walrus Powers to stop him he traps them under the ice which nearly kills them.
- In "Tazzy Chris" Zach sees a headline ready the Wild Kratts will be tagging the endanger Tasmanian Devil. Seeing how scary they look he travels to Tasmania and steals them all to power the T-Devil security bots. In the end, the Wild Kratts bait the T-Devils with decomposing food to free them.
- In "Let the Rhinos Roll" Zach rounds up dozens of black rhinos and fits them out with body armor to create an army of living bulldozers so he can knock down trees and build a parking lot. In addition, he gives a baby rhino calf (whom Martin names Nubs) a contact lens camera so he can spy on the Wild Kratts crew. When Chris sneaks into his plane, Zach restrains him and tells Chris his plan; Zach also states that the contact lens has a GPS that he intends to use to find and destroy the Tortuga. The other Wild Kratts manage to find out about Zach’s plan and free the rhinos by luring them into a mud pit. Zach lands the mud and demand that someone get him out, then one of the rhinos uses its horn to send Zach up into a tree.
- In "Falcon City" Zach is first seen in the park trying to eat a cookie, but some pigeons take it. Later, when he orders his Zachbots to clean his building, it causes a problem for a falcon family and their chick (whom Martin names Fluff). The Kratt brothers get to work stopping the Zachbots, and then Aviva gets an idea to reprogram the Zachbots, causing them to fly south, taking Zach along with them.
- In "Koala Balloon" Zach falls ill with a cold, so he goes to Australia to get some Eucalyptus leaves to make Eucalyptus tea. But when he sees a baby koala in his potted Eucalyptus plant he orders his Zachbots to send it away on balloons over the Australian outback.
- In "Cheetah Racer" he spies on Aviva from his hidden spy cloud, overhearing how Aviva intended to create a vehicle that could outspeed a cheetah. Aviva and Zach argue, with it being decided to settle it over a race. Zach cheats by using Blur the cheetah to power his all-terrain vehicle, but Martin discovers this and put a stop to it, forcing Zach to activate the rockets to speed up, but Zach eventually loses control and ends up flying away from the race course, later reappearing to demand a rematch.
- In "A Huge Orange Problem" Zach's seen flying over the jungles of Borneo in his jet and decides he wants a side table made from black wood. So he orders his Zachbots to cut down all the trees until they find one with black wood. The Wild Kratts put an end to his scheme and an orangutan tosses into a tree in the middle of a lake, surrounded by crocodiles.
- In "The Gecko Effect" Zach spies on the Wild Kratts and states that he could invent anything that the Wild Kratts can and lists the Miniaturizer as an example, believing that means the Miniaturizer should be his. When the Wild Kratts Miniaturize themselves to go look for the secrets of the gecko's toe powers, Zach sneaks in the Tortuga and claims the Miniaturizer. When the Wild Kratts return, Zach traps them in a jar and says that he'll keep them as his trophy pets and every now and then, shrink some animals for them to play with. Martin manages to trick Zach into dropping a normal-sized gecko into the jar, claiming that it’ll freak him out. While he contacts the other villains to brag about the Miniaturizer, the Wild Kratts escape and return to normal size. Then, Zach is scared off by two moon rats that accidentally gigantified themselves with the Miniaturizer.
- In "Quillbur's Birthday Present" Zach is in Africa once again on an animal collecting trip. When he orders the Zachbots to go get the animals, they all collapse because Zach forgot to charge them, leading to Zach thinking of doing the collecting himself when he sees some balloons floating by and gets an idea. When he overhears the Kratt brothers making preparations for Aviva's birthday party, Zach steals some of the balloons and begins tying them to animals for his robots by airlifting them of the ground so that they'll float up into his blimp. The Wild Kratts catch onto his scheme and uses Porcupine Powers to pop the balloons and save the animals, refusing to give up, Zach rams his blimp into Martin, taunting him that he’s not so tough without his quills, only for it to be revealed that Martin still had one quill left, which pops the blimp and sends Zach flying away.
- In "Race for the Hippo Disc" Zach is seen canoeing through an African river with one of his Zachbots looking for a new animal invention, then, the Hippo Disc falls out of the sky and lands on Zach’s head. Knowing that he could unlock the secret of the Creature Power technology for his own use, Zach is delighted, until he's attacked by an angry bull hippo, but he is saved by Chris and Martin. Seeing that the Wild Kratts are looking for the lost Hippo Disc, he lets them lead him to it and steals it easily. Later that night, while trying to analyze the Disc, he is attacked by a hippo and gets stuck in a tree. Later, a charging hippo sends him flying into Martin, getting hold of several Creature Power Discs in the process and even though the Wild Kratts get them back, Zach captures a hippo calf whom Martin named "Hipster" and threatens to take him away if they don't hand over the Discs. Chris gives in and gives Zach the Disc case, whom quickly flies away in his jet. As he is happy at his supposed victory, Zach opens the case, only to find out it’s full of cookies.
- In "Creature Power Challenge" Zach attempts to ruin the brothers' fun by scattering a mud wallow everywhere, only to make things better for a rhino and elephant. Then he decides to ruin their fun by using Disrupt-o-bots to activate past transformations to ruin Chris and Martin's Creature Power Challenge and to keep the crew from interfering he hacks into their frequency which prevents them from communicating with them.
- In "Shadow, the Black Jaguar" Zach wants a large black cat to use as the spokesmodel for his new line of Zachbots, so he spies on the Wild Kratts to find a black cat, but after Chris and Martin start arguing over which cat species to Creature Adventure with, Zach decides to search for one himself and finds a black jaguar.
- In "Aqua Frog" after cleaning out his jet, Zach is left with barrels of toxic sludge which he decides to dump into the river which threatens all the animals downstream in Frog Water Pond.
- In "Rocket Jaw Rescuer of the Reef" Zach roboticizes many parrotfishes and makes them munch off all the coral in the reef of the Caribbean Sea so he and Donita can sell coral themed jewelry.
- In "Skunked!" Zach is working on his new Bubble Bot, only to get a call from a spotted skunk, whom Zach thinks it the Wild Kratts at first. When he sees that they've left their Creaturepod and Buzz Bikes in the middle of the desert he decided to test out his new invention and go to the desert to steal their technology. Then he hears that their headquarters is infested with skunks he decides steal the Tortuga itself, but he can't get it out of hover mode so he decides to copy their secrets onto his flash drive and escape in his own ship.
- In "Gila Monster Under My House" after overhearing how strong a Gila monster's jaw is compared to a power wrench, he decides to steal all the Gila monsters in the desert and use them as living batteries for power wrenches.
- In "Mosquito Dragon" Zach tries to hack into the Wild Kratts database, but no luck. Then after a mosquito bites him, he gets the idea of creating mosquito robots to steal computer data from the Tortuga.
- In "Under Frozen Pond" Zach calls Donita and Gourmand, informing them about their annual villains' meeting to discuss how to defeat the Wild Kratts once and for all. He decides to hold the meeting on top of a frozen pond in the middle of the freezing wilderness, believing that there will be no animals nearby, and also unaware that the Wild Kratts and some Wild Kratts Kids are right under the water below them. The heroes soon resurface and return to their normal sizes. The villains spot them and claim that the pond is their spot, even though the Wild Kratts were there first. So they decided to settle this over a game of ice hockey, where Zach cheats twice but doesn't care. But the villains end up losing anyway and they go their separate ways with Zach stating, "This was a horrible place for a meeting anyway!"
- In "Osprey" When Zach sees that the Wild Kratts have lost their keys in the water, he sends his Zachbots out to search for them so he can steal their technology once again. And to keep the crew from contacting Chris and Martin he casts a communication blocking net, but they soon find out, so Zach orders one of his Zachbots to cut down the tree where the baby osprey "Fluffy Flyer" is.
- In "Bandito the Black-Footed Ferret" After Martin's mishap with Aviva's Stone Digger leads to the discovery of an unknown colony of endangered black footed-ferrets, Zach decides to steal them so he can outfit them with robot parts to steal stuff.
- In "The Amazing Creature Race" Zach is be forced to exercise (doctor's orders) hating running and watching the Wild Kratts on his big screen he sees they're planning a race to see which animal is the best all-around runner. So he builds armor to fit out the animal who's the best who appears to be the pronghorn antelope. He then shows up and steals one Martin named "Pacer" right out from under them, but Chris and Martin spoil his fun by flattening his tires and leading a herd of stampeding bison his way.
- In "Lemur Legs" Zach and Donita are notified by Gourmand telling them that he'll be serving sifaka lemur legs as his main dish.
- In "Praying Mantis" Zach hears the Wild Kratts and Wild Kratt Kids Gavin and Ronan talking about praying mantis' and how they use their raptorial arms to catch prey. So he decides to mechanical create mantis arms of his own which uses to steal the miniaturizer and in addition has 2 of his Zachbots kidnap Koki and Jimmy. He then uses the miniaturizer to enlarge his Zachbots to attack Martin (whom has Praying Mantis Powers), then Aviva uses Mantis Powers herself only she's colossal which makes Zach super scared and sends him in his jet flying.
- In the special "Back in Creature Time Parts 1-2" Zach is bragging to his Zachbots about how he claims he's the greatest inventor ever, but he wants more inventions. So he orders his Zachbots to spy on the Wild Kratts while he works on his latest invention "An Invisibility Cloak". When he hears that Aviva has created a time machine he's outraged, claiming that was his idea, that's when he gets the idea to put his invisibility cloak to the test. So he travels to the Philippines and sneaks into the Tortuga undetected, where he surprises Koki, hits the mute button so they communicate with the guys, captures her and Jimmy and travels back in time so he can trap Chris, Martin and Aviva back in time. Once back in time he puts his plan into action, by having one of his Zachbots hide and wait to capture Aviva while he tells Chris and Martin that he's trapping them in time by jumping back to the future and disintegrating their end of the time machine. Fortunately with the help of Tasmanian Tiger Powers they are able to stop Zach and get back home as he flies away on his Zachbot.
- In the holiday special " A Creature Christmas" Zach, Donita, Dabio and Gourmand have teamed up in a holiday plot to steal the Wild Kratts baby animal friends by trapping them in giant Christmas ornaments, hanging from a robot tree in front of a mall owned by Zach called "Varmitech Village". After Chris, Martin and Aviva's plan spit up to stop them backfires so they regroup and head to Varmitech Village where they undecorated the tree setting the animals free. As the villains watch the Wild Kratts play happily with their baby animal friends they are very annoyed, though they expected this so they pretend to be touched by their animal friends and say that they'll do a one time kindness and help them return their animals friends. But when the villains present the Wild Kratts with a present for each of them only for them to find out they've been tricked. So then the villains take all the Wild Kratts stuff, except the Creature Power Discs letting the Wild Kratts keep them to remind them of their defeat. The villains then leave them on a large ice float in the middle of the ocean and return to redecorate their tree. But the villains overlooked Aviva's latest invention which is in Martin's pocket; a keychain button designed to summon his and Chris' power suits whenever they need them. With their suits back, they use their creature powers to get back much to Zach surprise, and the brothers un-decorate the tree yet again. Zach's Zachbots and Donita's mannequinbots try to stop them, but Jimmy activates the Tortuga disrupt-o-blast which stops them. But Zach has one final trick where he activates his robot tree to stop them, but the brothers manage to defeat it. But the villains refuse to be defeated, unfortunately they forget the baby animals have names and the villains are soon trampled by the baby animals in an adorable defeat. As they flee the mall in fear Zach exclaims "Who needs Christmas anyway!"
- In "Animals Who Live To Be 100 Years Old" Zach realizes he's getting old when he sees a wrinkle on his face, when Donita tells him there is no fountain of youth he believes that if anyone can find it the Wild Kratts. Coincidentally he hears they're looking for animals that live over 100 years old, so he decides to do his own research and stay one step ahead. First he tells them that he's going after a salamander called "The Human Fish", but its really a trick so he can really go after the bowhead whale; who can live to over 200 years old. Once they get there after stopping him, Zach angrily overrides their ship sending them into the Sea of Japan where they find a school of immortal jellyfish who the creature power to live forever. Even Zach thinks by eating them he'll live forever, his plan backfires after he almost eat Chris and Martin.
- In "Panda Power Up!" Zach wants to make robotic stuffed animals out of real live animals and when he sees Aviva's stuffed panda toyland on his ship's windshield he decides to use Pandas as his model. Once in China he soon bumps into the Wild Kratts' Tortuga and sees their engine control panel is open he orders his Zachbots to drain their power. Then he when he finds Chris, Martin and Aviva he steal's Chris' Creature Pod, the Buzz Bike's Power along a mother Panda and Martin (in his panda suit) and leaves Chris and Aviva alone in the wild with no power or communication. Fortunately with help of using bamboo as excess energy, they are able catch up with Zach, release Martin and the others pandas and even retrieve Aviva's stuffed panda toy.
- In "Golden Snub-Nosed Monkey Man" Zach plans to capture the legendary yeti to put on display and charge money for admission. But when he thinks he's found one, he soon discovers that its really Martin in a Golden Snub-Nosed Monkey creature power suit. When Martin tell Zach that he'll tell everyone who he is, Zach threatens to do bodily harm to Martin's monkey friend Blue Goggles. But soon Chris and Aviva show up and defeat Zach and save Martin and Blue Goggles.
- In "Red Panda Rescue" Zach wants to get Donita a weasel stole for her birthday. So he hacks into the Wild Kratts computer system to see what type of weasels there are and when he sees Chris with a baby red panda he decides that he wants to steal it. So he and his Zachbots break into the Tortuga and steal her right out from under the crew and puts Aviva, Koki and Jimmy Z in a communication blocking net. But before he can get away, Chris and Martin arrive and Zach quickly has his Zachbots form a protective circle and hides the red panda cub (whom Martin named Lost and Found) inside one of them. A chase soon begins as Chris and Martin pursue after Zach and his Zachbots, in the end, Lost and Found is rescued and Zach is left with no present for Donita.
- In "Musk Ox Mania" while going through his "Finders-Keepers" collection, Zach realizes he doesn't have anything from the Wild Kratts. By spying on them, Zach hears that Chris has lost his "Creature Souvenir" collection, although he’s initially not interested in it, Zach decides that it’s worth stealing after Chris mentions that it helps to activate Creature Powers. At the Arctic, Zach manages to get his hands on it and Chris asks for it back, but Zach refuses, but then, a pack of Arctic wolves show up and try to attack Zach, thinking he is a musk ox due to his enormous hairy coat. Zach has his Zachbots for a defensive ring around him so that he can safely get to his plane, but the lead musk ox who also thinks Zach is a musk ox, charges at him believing him to be a challenger and destroys his Zachbots leaving Zach unprotected against the Arctic wolves, making Zach give up his coat and the Creature Souvenir collection before fleeing.
- In "Polar Bears Don't Dance," Zach's eyes are shown to be a lighter green than in subsequent episodes.
- He is also shown to have fans that support his showing of his animal robots, which are not Zachbots.
- In "Mystery of the Weird Looking Walrus," Aviva claimed that Zach has six toes on his left foot, but in another episode, he is depicted with five toes.
- In a flashback to his childhood, Zach is seen with a normal skin tone, freckles and braces.
- Zach probably has a fear of animals, since he often screams when he is near one.
- Black balloons help lift Zach's spirits.
- Zach has known the Kratt brothers since they were children.
- Zach went to science camp with Aviva when they were children, and from there he developed a rivalry with her.
- Zach has been in the most episodes, which could lean on him being almost the main antagonist of the series.
- As a child, he was using animals to power his inventions.
- Donita and him are friends (more or less).
- Donita occasionally refers to Zach by his real name, "Zachary."
- Zach's favorite food is tomato soup, as seen in "Skunked!."
- As seen in "Liturgusa Krattorum" and "A Creature Christmas," Shadow doesn't appear to be afraid of Zach.
- Maybe Shadow likes Zach.
- It is hinted that Zach may have a crush on Donita