Merrow Bonegnawer
{B}
Creature — Merfolk Rogue
Oracle Text
{T}: Target player exiles a card from their graveyard.
Whenever you cast a black spell, you may untap this creature.
Watch Out
Cast trigger fires even if counteredWatch Out
This triggers when the spell is cast, before it resolves. Even if the spell is countered, the cast trigger still resolves. Copies of spells are not cast, so they won't trigger this.