Mavel, "Professional" Pixie

Flying
Whenever a creature attacks a player other than you it gains +1/+1 until end of turn for each Dust counter on it.

{t}: Tap target creature and put a Dust counter
on it. Create a tapped Treasure token.

{u}{b}{g}: Untap Mavel. Put a Dust counter on it for each other creature with a Dust counter.