Guidey, Slayer of the Elven

Whenever Guidey, Slayer of the Elven attacks, you may destroy target permanent an opponent controls. If that permanent is an Elf creature, you may put a +1/+1 counter on each Goblin creature you control.
"This elf. We slay elf. We no like elf. We no accept invite to elvish house party unless we go to slay elf. Any questions?"