The final version of the Predator costume required a tall actor, but before Kevin Peter Hall stepped into the final suit, Jean-Claude Van Damme shot scenes as the Predator. And he looked especially insane in the "cloaked" Predator outfit, which was bright red.
Steve Johnson and Matt Winston explain the history of the Predator costume with the original, "terrible" design and a then unknown Van Damme in the suit. The cloaked suit needed to be red to distinguish it from all of the greenery, and apparently no one explained its purpose to Van Damme. The future action star thought he'd be portraying a giant red flea for the entire film—and was very vocal about his displeasure. It's one of the reasons the team filming Predator thought the movie was going to be awful.
[via Comic Book Movie]