Insulin Imp

•Flying
•When Insulin Imp enters the battlefield, distribute two -1/-1 counters among one or two target creatures. (Representing a sudden drop in blood sugar!)
•At the beginning of your upkeep, you may pay 2 life. If you do, put a +1/+1 counter on Insulin Imp. (It's snack time!)
{bull}Whenever a player casts a spell with X in its mana cost, Insulin Imp gets +X/+X until end of turn. (Sugar rush!)
"It loves sweets, but oh, does it have mood swings!"