Zach has a very thin build and very pale skin; he is barely taller than Chris. He has black, shiny hair and green eyes. He also has a small, black goatee. He typically wears a black turtleneck sweater, gray slacks, and black pointed shoes. 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 inventor/mind," even programming his computers to refer to him (Zach) as "my greatness," despite 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; 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 a deadly arctic storm (Polar Bears Don't Dance), and drowning 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 Aviva's and/or Donita Donata's. His arrogance is not unfounded, however, as he actually is a pretty good inventor, since he is 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; more so than the other villains. His primary means of travel by air 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.
- Zachbots (Robotic henchmen)
- Mind-Control Skull Caps
- Mosquito Bots
- Disruptor Beam
- Bubble Bot
- Robotic Tree
- Hypnotic Eyes
- Invisibility Cloak
- Robotic Vest
- Cloud Camouflage
- Animal Vac
- Communication Jamming Net
- Robotic Mantis Arms
- Aardvark Town
- Flight of the Draco
- Mystery of the Weird Looking Walrus
- Platypus Cafe
- Polar Bears Don't Dance
- Honey Seekers
- Bass Class
- Tazzy Chris
- Let the Rhinos Roll!
- Falcon City
- Koala Balloon
- Cheetah Racer
- Mimic (video flashback)
- A Huge Orange Problem
- The Gecko Effect
- Quillber's Birthday Present
- Race for the Hippo Disc
- Creature Power Challenge
- Happy Turkey Day (mentioned)
- Shadow: The Black Jaguar
- Aqua Frog
- Rocket Jaw: Rescuer of the Reef
- Gila Monster Under My House
- Mosquito Dragon
- Under Frozen Pond
- Bandito: The Black-Footed Ferret
- The Amazing Creature Race
- Lemur Legs
- Praying Mantis
- Back in Creature Time, Part 1: Day of the Dodo
- Back in Creature Time, Part 2: Tasmanian Tiger
- Liturgusa Krattorum
- Panda Power Up!
- A Creature Christmas
- Puffin Rescue (mirage)
- The Last Largest Lobster (mentioned)
- Golden Snub Nosed Monkey Man
- Red Panda Rescue
- Spirit Bear (mentioned)
- Animals Who Live To Be 100 Years Old
- Musk Ox Mania
- Creatures of the Deep Sea Part 1 (flashback)
- In Polar Bears Don't Dance, Zach's eyes are shown to be a lighter green than in subsequent episodes.
- In Polar Bears Don't Dance, Zach has fans that support his showing of his animal robots, which are not Zach-bots.
- 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 refers to Zach by his full name, "Zachary".
- Zach's favorite food is tomato soup, as seen in Skunked!
- In Liturgusa Krattorum and A Creature Christmas, Shadow seems to like Zach. In fact, he might be the only baby animal who likes him (Zach).