A trenchcoat is a long, waterproof coat, typically associated with noir detectives in fiction.
Most incarnations of the Ninja Turtles wear trenchcoats as disguises when traversing the streets, as they cover most of the Turtles' bodies. Of all of the Turtles individually, the trenchcoat is normally associated with Raphael due to his "topside" adventure wearing one in the original feature film.
See also
- Don, the Undercover Turtle, the first TMNT action figure to feature a Turtle in a trenchcoat.