This idea is inspired by ribbons in Pokémon. 

Ok so, the idea plays out like this.

 Your creatu may earn a special ribbon, (By completing certain objectives, or raising a skill to a level.)

These would be extremely hard to get and upon completing changes the effect of said creatu to the corresponding ribbon effect.  (As adults)

It would be a small difference in appearance to creatus who have mastered certain skills. Giving them a tiny ribbon. 

It might be a bit of work for the Artists.

Ofc, this was just a silly thought. I don't have it all exactly planned out, but I am curious to see what you guys think. 

Feel free to voice your concerns. :P 

Why it would or wouldn't work.