Newtralizer

The Newtralizer (Real name unknown) is a character that debuted in the 2012 TV series. He is an enemy of both the Turtles and the Kraang. He is an amalgam of characteristics of a rejected toy design for Playmates Toys by Ryan Brown and a character created by executive producer Ciro Nieli whilst in elementary school. Due to The Newtralizer's costume, he is likely a parody of Marvel's The Punisher with inspiration provided in part by Judge Dredd. The most obvious feature in this respect is the skull-like pattern on the Newtralizer's chest that resembles the emblem on the chest of the Punisher's costume. (See also "The Good, The Bad and Casey Jones "for a similar homage/parody)

Appearance
The Newtralizer is a heavily armored, alien Fire Belly Newt. He is primarily black, with an orange underbelly. The coloration of his underbelly forms a skull pattern. The Newtralizer is very muscular and bulky, easily dwarfing the Turtles in combat. He appears to be very intelligent, capable of using Kraang equipment and weaponry without issues.

His armor set includes a belt, a pair of shoulder plates (the right plate is far larger than the left), two straps that connect the belt and shoulder plates, a pair of armored bracelets, a pair of leg holsters with pouches and ammo types attached to them, and a pair of axe blades attached to his tail. He also wears a backpack with an antenna sticking out. It is likely a radio, but its exact purpose is unknown. He also carries three Kraang tentacles as trophies tied to his belt.

History
The Newtralizer is a resident of Dimension X. He was captured by the Kraang after considerable effort and imprisoned in a secret prison facility on earth because he had a tendency to devour every living thing he met - including the Kraang. In an attempt by Donatello, to free Kirby O'Neil, Newtralizer was also accidentally freed and continued his hunt to rid this plant of the Kraang.

Eventually Newtralizer raided a Kraang facility and ​​on this occasion made an acquaintance of the mutant Slash. After they had joined forces Newtrailizer talked to his new partner in the human's language and Slash accompanied him on his hunt for the aliens. However, Newtralizer's thuggery, regardless of the consequences against the innocent people in the area, led to this team to very quickly fall apart.

Operation: Break Out
The Newtralizer's first appearance in the series is in Operation: Break Out, as a prisoner of the Kraang.Donatello inadvertently releases him from his cell when he picks the lock to a secret Kraang lab, and he promptly goes on a rampage. The turtles ultimately manage to defeat him, but he survives and escapes from the lab.

Metalhead Rewired
Newtralizer's next appearance is in Metalhead Rewired as one of the detained mutants in the Kraang prison. After Metalhead frees all of the mutants, he escapes from Kraang captivity once again.

Newtralized!
The Newtralizer returns and teams up with Slash against Raph and Casey. It is shown that he had helped Slash escape from a Kraang prison, which is what lead to them working together. Newtralizer and Slash viciously assault numerous groups of Kraang and steal their supplies to create teleportation devices. Newtralizer then plots to take control of the Kraang's newest weapon to destroy them and anybody who gets in his way. He is able to get a hold of it and destroys the Kraang in the area and attempts to use it on the Turtles. Casey arrives and launches a puck with a bomb strapped to it into it. Despite the damage sustained to the teleportation device, Newtralizer is able to escape.