Weird

Create a 0/0 black Weird creature token with Indestructible, Annihilator 1, "this creature can't
be blocked", and "whenever this creature deals
combat damage to a player, remove a +1/+1
counter from it, then, if it has 0 +1/+1 counters
on it, it loses indestructible". It enters the battlefield with 5 +1/+1 counters on it.
Spells your opponents cast that target this spell
cost {3} more to cast