Skin
Skins are only unlocked in Rayman M/Arena with half of the characters earning them who are: Globox, Henchman 800, Teensies, Henchman 1000 and Rayman. Each character unlocks up to 3 skins, except Rayman, who only gets one. Each skin (but Rayman's) changes the beat for the character's theme to what it is most suited to. (E.g. Globox has his strawberry skin and is racing in the Extreme League. The beat for the Extreme League racing is fast, and the beat for the Advanced League is light and watery. Globox's skin will change the beat from the Exteme League to the Advanced League.) But if it is in its League, it will change to the Beginner League's beat (thumping in the background). The skins do not have this effect on battles. It unoticable, but may be true that the skins in their league make the race slightly easier.