Adaptational Nice Guy: After Donnie's retromutagen experiments causes explosions and Raph extinguishes some fires, he helps Donnie get upstairs to have some of their mother's tea to help with Donnie's coughing fit.
Evil Counterpart: Slash is openly referred to as an Evil Twin to Raphael, being an ill-tempered mutant turtle, his turtle DNA being the source of Raphael's mutation, Raph's human DNA the source of his humanoid form.
For Want Of A Nail: Due to Raph colliding with Leo in an attempt to get the mutagen, Leo doesn't get on a side adventure trying to get the mutagen, and doesn't have a tea party.
In Spite of a Nail: In "Slash and Destroy", Spike gets mutated into Slash when Raphael angrily confiscates mutagen from Donnie's lab. Here, the mutation happens when after Donnie's attempted retromutagen experiment, Donnie's stumble crashes into a table holding a canister of mutagen which spills on the floor of his lab. Spike crawls out of Raph's room, attracted by the glow of the mutagen and gives it a taste.
The Nose Knows: Slash is able to track the scent of mutagen rather than needing Donnie's tracker.
Seen It All: While Miwa is understandably surprised by Slash, she very quickly shrugs it off when he and Raph explain the situation.
