Majestic Auricorn (Ikoria: Lair of Behemoths)

Creature Ñ Unicorn - Mutate {3}{W} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)
Vigilance
Whenever this creature mutates, you gain 4 life.