Fiend Steed

When you regain Hit Points from a level 1+ spell, the steed regains the same number of Hit Points if you're within 5 feet of it.

Melee Attack Roll: Bonus equals your spell attack modifier, reach 5 ft. Hit: 1d8 plus the spell's level of Necrotic damage.

Wisdom Saving Throw: DC equals your spell save DC, one creature within 60 feet the steed can see. Failure: The target has the frightened condition until the end of your next turn.