Transmogrifying Wand enters the battlefield with three charge counters on it.
{1}, {T}, Remove a charge counter from Transmogrifying Wand: Destroy target creature. Its controller creates a 2/4 white Ox creature token. Activate only as a sorcery.
If the target creature is a legal target but can’t be destroyed, most likely because it has indestructible, its controller gets an Ox token and gets to keep that creature.
If the target creature is an illegal target by the time Transmogrifying Wand’s ability tries to resolve, the ability doesn’t resolve. No player creates an Ox token.