Caustic, Toxic Trapper

+1: Create a 1/3 Colorless Trap artifact creature token with Infect and "When this creature dies put a -1/-1 counter on up to one target creature".
-3: Tap each creature target player controls, then put a 1-/1- counter on each of them
-7: Put 5 -1/-1 Counters on each creature you opponents control,