Funny thing about womp rats in Namco's Star Wars – they don't exist. The creatures that most players assume to be womp rats on Tatooine – the first enemy type you encounter in the game – are actually identified in the manual as Elepads. Described literally as "the first enemies to stand in Luke's way," we can only presume them to be talentless, bloodthirsty cousins of Max Rebo. But even though Elepads are definitely not womp rats, they still serve as better in-game womp rats than the green monster thingies Super Star Wars has to offer. You even fight a huge mutant version as a boss.
Worth noting: Before the 1997 Star Wars Special Edition, the most mainstream reference for a womp rat was probably Marvel's Star Wars #17, a brilliant pre-Rebellion Luke Skywalker story by Chris Claremont. They were green there, too. But that's dumb.