The Devil (Tom & Jerry)

"Devil" refers to a symbolic villain found in Tom & Jerry and represents the evil side of Jerry Mouse, being a horned version of the protagonist rodent with green fur and a habit of appearing in order to try and tempt Jerry into doing evil - he may also be an embodiment of jealousy as he appears often when Tom is distracted and thus ignored Jerry (usually when Tom is lovestruck).

"Devil" is not an official name (the creature lacks one) but is fitting as the creature is clearly meant to represent a Devil (small demonic creatures popularly believed to tempt people into doing evil - in fiction they are often opposed by an angel, representing a character's conceince).