In one of the promo screenshots of the music minigames, i spotted a Rabbid with a familiar face

The two rabbids that are marked with an red circle (they are pointed with some red arrows, as you can see) make some familiar faces. They are making a face of an rabbid sprite that went unused in the final game (probably was a leftover from the cancelled rayman 4 prototype). Let me show it for you.

The unused sprite is the one i'm showing here now. If you focus more on the promo screenshot from the final game, you can see that the faces of those 2 rabbids and this unused sprite faces are nearly identical. This may not be very notorious on the screenshot i used, but if you see the back of the boxart of the final game, you can note it more clearly.