Spike began life as a regular pet turtle of mutant, Raphael. After exposure to mutagen, he was transformed into the talking, humanoid turtle, Slash. This change initially pitted him against Raphael and the Turtles, but he managed to sort out his issues, and learned to fight for good by becoming leader of his own group, the Mighty Mutanimals.
Transformation into Slash
Spike was almost killed when one of Donatello's experiments went wrong which made Raphael really mad. Raf stormed off with Spike and Donnie's last canister of mutagen, leaving Donnie feeling really bad. Raf spoke to Spike until Leo came to tell Raf he needed to help clean up.
Raf left the room and as he did he slammed the door, which knocked the mutagen off the table, breaking on the floor. Raf later returned to the room to find Spike gone and the broken mutagen canister on the floor. Spike emerged from the shadows, startling Raf a little. The two talk for a while befoer Leo came to ask if Raf wanted to go on a mission, but he refused. Raf wanted to tell his brothers about what happened, but Spike changed his mind, telling him they could be better partners than when he was with his brothers because they don't understand him the way he did. Then while his brothers were out on a mission, Raf gave Spike a black mask and fist wraps, then he opens his weapons box. He told Spike, "take your pick" in which Spike chooses a metal club. Spike then later changed his name to Slash. Just before Raf and Spike left on their mission, Spike took one more look at the photo of Mikey, Leo, and Donnie that was hanging in Raf's room.
On their mission, Raf ended up running into Leo literally and the two start arguing while Mikey and Donnie watch. Slash sneaks up on Donnie and kidnaps him without Mikey ever knowing. Raf leaves the fight and goes to look for Slash, but Slash finds him hiding Donnie mask in his hand. Mikey appears out of no where and tells Raf Donnie is missing. Slash tries to tell Raf he doesn't need them but, Raf told him that his brothers came first, which made Slash mad, causing him to attack Mikey. Raf slammed into Slash to keep him from killing his brother. Slash still tried to get Raf on his side, but Raf refused and went to look for Donnie with Mikey.
They find him battered, but alive, while also finding beside him claw marks, which were left by Slash. While Raf fixed Donnie's arm, Mikey thought he heard Leo, but it was really Slash mimicking Leo's voice. Raf went to look for Mikey and found him dangling of the side of the building, but still alive. Raf ended up taking on Slash in a head to head battle where he got knocked around and almost killed, but thanks to Leo coming to his rescue he was able to knock Slash off the building. Raf checked on Leo who was hurt in the fight, but when he went back to the edge of the building with his brother, Slash was gone; all that was left was a crater in the ground, where he had fallen.
- 102. Rise of the Turtles, Part 2 (as Spike, no lines)
- 103. Turtle Temper (as Spike, no lines)
- 110. Panic in the Sewers (as Spike, no lines)
- 111. Mousers Attack! (as Spike, no lines)
- 122. The Pulverizer Returns! (as Spike, no lines)
- 124. Operation: Break Out (as Spike, no lines)
- 125. Showdown, Part 1 (as Spike, no lines)
- 126. Showdown, Part 2 (as Spike, no lines)
- 207. Slash and Destroy (as Spike, no lines, and Slash)
- 211. Metalhead Rewired (as Slash)
- 217. Newtralized! (as Slash)
- 226. The Invasion, Part 2 (as Spike, photo)
- 312. Battle for New York, Part 1 (as Slash)
- 313. Battle for New York, Part 2 (as Slash)
- 316. Clash of the Mutanimals (as Slash)
- 325. Annihilation Earth!, Part 1 (as Slash)
- 326. Annihilation Earth!, Part 2 (as Slash)
- 414. Earth's Last Stand (as Slash)
- 418. Mutant Gangland (as Slash)
- 425. Requiem (as Slash)
- 426. Owari (as Slash, no lines)
Total appearances: 21.