Teenage Mutant Ninja Turtles wouldn't be anything without its villains, as one of them provided the Mutagen necessary for the Turtles to exist as fans know them today. Many of the universes' villains are humorous, villain-of-the-week types that test the Turtles and bring them together without posing much of an actual threat, while other enemies possess terrifying strength that come close to, or succeed in depending on the timeline, killing the Turtles.
Source：https://www.cbr.com/underrated-tmnt-villains/
