The Rat King discovers a canister of mutagen and plans to use it to create a race of rat-mutants to steal food for his sewer kingdom.
Tropes:
- Cartoon Cheese: The cheese in the crates all have that stock design.
- Grail in the Garbage: Apparently the Rat King has had a canister of mutagen in his possession this whole time and he's dismissed it as worthless "green junk" up until now.
- Rat Folk: The Rat King's plan is to create a race of rat mutants like Splinter, starting with Vernon and Irma.