Russell "Russ" Gregory (2012 TV series)

History
Jake is a hunter, tracker, and combat specialist. According to him when he was telling his tales to the Turtles, he lost his eye while fighting a crocodile with his bare hands when he was 8 years old. Years later he married a beautiful women named Kaya. One day when he was hedding home, after hunting a water buffalo, he found a strange canister of ooze and brought it home to show Kaya what he had found.

Then their house was under attack by Kraang droids, who were after the canister of ooze, and they were taken by the Kraang droids to their lair where Jake watches in horror as the Kraang experimented on Kaya.

When the Kraang were about to experiment on Jake he made his escape, during the escape he made his way through a pen of kangaroos, and slipped into a tank of ooze and became a mutant kangaroo. He used his new kangaroo abilities to escape the oncoming Kraang droids.

After his escape he vowed to avenge his wife by hunting down all aliens and made his new home in a warehouse in Sydney under the alias "Walkabout".

Years later he is hired by the Shredder to assassinate some aliens (the Turtles). He tracks the Turtles down into the sewer and finds them spying on a troop of Kraang droids with April and Casey. After a little while, April comes to sense Walkabout's presence, and that's when he attacks them by surprise. While the Turtles do put up a good fight, they are no match for him and his pragmatic fighting style, until they were discovered by the Kraang droids

Quotes
[Shredder and two of his Foot-Bots enters Walkabout's warehouse; it is dark, and only Walkabout's eyes are visible]

Walkabout: Who dares enter my home?

Shredder: I've come along way to find you, and I was told that you are the one who could handle an "alien" problem.

Walkabout: You are told correct, but for this I charge a great deal of money.

Shredder: I am completely aware of it.

[one of the Foot-Bots brings over a briefcase full of money on the table; Walkabout opens it with his hunting knife]

Walkabout: You have engaged my valuable services, mate. Just tell me where I find these aliens.

Allies

 * Leonardo -
 * Raphael -
 * Michelangelo -
 * Donatello -
 * Splinter -
 * April O'Neil -
 * Casey Jones -
 * Leatherhead - Walkabout and Leatherhead don't get along, due to his hatred for crocodiles, but still considers him a reliable ally.
 * Mondo Gecko -

Enemies

 * Shredder -
 * The Kraang -