Aminatou's Guardian

A Large spectral silvery moth appears and hovers for the duration in an unoccupied space of your choice that you can see within range. The moth occupies that space.

Any creature hostile to you that moves to a space within 10 feet of the moth for the first time on a turn must succeed on a Dexterity saving throw. The creature takes 8D4 force damage on a failed save, or half as much damage on a successful one. The moth vanishes when after 1 minute.