Newtralizer

"RAKA RAKA RAKA!!!"

- Newtralizer's battle chant "Now do you see? You see what I'm capable of? AHAHAHAHA!"

- Newtralizer after supposedly killing Michelangelo

K'Vathrak, better known as the Newtralizer, is a character that debuted in the 2012 Teenage Mutant Ninja Turtles TV series. He is a violent Salamandrian criminal who is an enemy of both the Turtles and the Kraang.

Past
K'Vathrak, prior to being known as the Newtralizer, was a traitorous Salamandrian war criminal who worked as a personal assassin to Lord Dregg. At a point unknown, K'Vathrak was captured by the Kraang and imprisoned on Earth in a secure Kraang base.

Season 1
In an attempt by Donatello to free Kirby O'Neil, Newtralizer was also accidentally freed and he promptly went on a rampage. The turtles ultimately manage to defeat him, but he survives and escapes from the lab and continued his hunt to rid the Earth of the Kraang.

Season 2
Newtralizer was later detained in the Kraang prison. After Metalhead frees all of the mutants, he escapes from Kraang captivity once again.

In "Newtralized" 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. Once the Turtles leave, the Newtralizer suddenly teleports back, infused with energy from the teleporter, implying that he had become stronger.

Season 5
When Worlds Collide: It turns out the Newtralizer didn't die after his last meeting with the Turtles and returns more powerful than ever. He now has the ability to absorb and shoot eletricity. He is the one who took Sal Commander's left eye and his real name is K'Vathrak. He nearly eats Bishop's Utrom brain and desintegrates Michelangelo but the latter reappears, still alive and with eletrical powers similar to K'Vathrak's. He is also allies with Lord Dregg, helps him launch his invasion on Earth and helps the Vreen kidnap Leonardo, Donatello, Karai and Sal Commander. While the rest of the gang is fighting Dregg and his Vreen, K'Vathrak, Mikey and Sal Commander fall into Dregg's ship core and the former two engage into a eletrical-powered battle until K'Vathrak knocks Mikey down and prepares to destroy him but Sal Commander manages to throw K'Vathrak into the core with his tail. Once K'Vathrak falls into the core, his eletrical powers overload the core and the ship starts getting ready to explode. The ship explodes and presumably the explosion kills Dregg and the Newtralizer for good.

Trivia

 * 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 infamous skull painting on the Punisher's costume.
 * Additionally, Newtralizer 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.
 * Newtralizer is one of the few villains in the 2012 TMNT series to have killed other living characters on screen, the others being Shredder (who killed both Tang Shen and Splinter) and Kavaxas (who killed Tatsu and The Hammer).