Crab of Purity

Kicker: {1}{u}
When Crab of Purity is summoned, remove all -1/-0, -0/-1 and -1/-1 counters from all creatures. If Crab of Purity is kicked, this only affects ally creatures and heals 3 to a player of your choice.
A crab of all things? I always thought angels were the purest creatures, but whatever.