Slimy Piper

Creature — Fungus Bard

Whenever this creature attacks, it gets +1/+1 until end of turn. If you control four or more creatures, it gets +2/+2 and gains indestructible until end of turn instead. (Damage and effects that say "destroy" don't destroy it.)

All throughout the glade, sprouts squelched happily along to the tune.