Grumble

Commentary:

Turning into a ball is a skill Red can teach. It’s easy for Blue to learn, though, because she started out already ball-shaped. It would be much harder for Yellow to learn how to do this, though it is still possible for him to do so. Turning into a ball doesn’t really have much practical application, but I guess if they want to squeeze through small holes Metroid style then that would be the best way to do it.