He is 47 (real-life) years old.
As his theme color is blue, Martin is always shown in blue apparel. Including creature suit, daily wear, jackets, scuba gear, even as a small child. His skin looks to be tanned while he has big blue eyes and sandy blond-brownish colored hair.
Most likely due to be the elder brother, Martin is taller then Chris.
Martin is the more "childish" brother, he's very fun and dearly loves all animals, mainly the babies! To the point of taking the time to name each and every one. He's been called an "Animal Lover", "Tree hugger", and "Clog". When it comes to animals he always tries to get into their heads and think like how they would in hopes of aiding whatever it is he and his brother must do.
But unfortuantly for him he can be just a bit ditzy and pretends to be prepared for anything, as shown some of the time during the series. Also, he pretends to be the "big brother" and "save" Chris from "danger". (Mystery of the Weird Looking Walrus). He also likes to play "hide and seek tag" (Mimic).
Mischevious and curious, Martin is very enthusiastic and a "Big ideas" type of guy. He's very impulsive, which may get him into trouble. But normally due to his "winging it" type of ideas, they have gotten out of a lot of trouble too. He is the comedian to Chris' straight man and like any good partnership, it is truly the brothers' differences that help make them the perfect team. Martin also likes to get into the mind of the animals ("Be the bear!", " be the rock!", "Be the walrus!" etc.). But, that has helped them, too.
He uses his animal knowledge, swimming skills, and creature powers to save the creature world. He also knows how to water ski, snowboard, Manta board (Octopus Wildkratticus ). He can also jump-on-his-brother-to-tag/catch him. And give piggyback rides for Jimmy Z! (The Gecko Effect)
Chris Kratt is both Martin's younger brother and best friend, whom which he does creature missions with.
Zach Varmitech & Martin have known each other since childhood (shown in the episode of Tazzy Chris) and are enemies. Zach usually refers to Martin as "Blue Boy". Martin can be forgiving to Zach even when he does something wrong.
Donita Donata & Gourmound are enemies. Gormound often refers to Martin as "blueberry".
Donita calles Martin "Martino" (Flight of the Draco)
Known Creature Powers
Crocodile, Giant Squid, Honey Guide, Polar Bear, Aardvark, Monarch Butterfly, Bass, Beaver, Draco Lizard, Cheetah, Basilisk, Blue Jay, Lion, Pigeon, Playtpus, Bat, Zebra,Proboscis Monkey,Peregrine falcon,Rock,Bat-eared Fox
- Apparently Martin may not be one of the best drivers out there, as seen in "Aardvark Town" when he drove over the ravine. He also did a bit of this off-screen in "Let the Rhinos Roll!".
- It is shown in "Honey Seekers" that Martin is right handed.
- He loves chocolate. As shown in "Zig-Zag" when Chris asked "You thinking what I'm thinking?" Martin said "That everything tastes better dipped in chocolate.".
And in 'To Touch A Hummingbird",he sips some of Gourmand's chocolate sauce that was suppose to be for the hummingbird eggs.
Martin: I think I'm going to name him The-big-strong-orange-guy-who-won't-let-us-get-back-to-the-tortuga.
Chris: That might be a little long.
Martin: Ya think?--From A Huge Orange Problem
Chris: Martin! Martin, do you realize what this proves?!?
Martin: *squeezing water out of shirt* Um, never let your brother blindfold you when you're floatin' down a river? -Platypus Cafe
Chris: You thinking what I'm thinking?
Martin: That we catch the first bus outta here? -Kickin' It With the Roos