Nettle Sentinel
{G}
Creature — Elf Warrior
Oracle Text
This creature doesn't untap during your untap step.
Whenever you cast a green 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.