On April 22, 2026, former Rare character designer Kevin Bayliss revealed that at one point during development, a kangaroo named Roo was planned to be playable but was dropped in favor of Pipsy the Mouse. He claimed she was taken out of the game purely for logic reasons, as the team felt it didn't make sense for a baby kangaroo to drive while wearing boxing gloves (he also noted that these boxing gloves were likely reused from a Thai boxer girl character he designed for a rejected pitch for Killer Instinct 3). Additionally, Roo was originally designed with realistic fur, but this was dropped due to how long it took to render the effect.