Innate Spellcasting. The undead spiked horror's innate spellcasting ability is Wisdom (spell save DC 11). It can innately cast the following spells, requiring no verbal or material components:

At will: detect magic, dispel magic, mage armor

1/day each: fear, hold person, blood mist transportation

Multiattack. The undead spiked horror makes two melee. It can also use Life Drain before or after making these attacks.

Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) slashing damage.

Spiked Appendage. Melee or Ranged Weapon Attack: +6 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 7 (1d6 + 4) piercing damage, or 7 (1d6 + 4) piercing damage when used to make a melee attack.

Life Drain. The undead spiked horror widens its bloody eyes and tries to suck the life essence out of one creature in its melee range. The target must succeed on a DC 13 Constitution saving throw (undead and constructs automatically succeed), or it takes 10 (2d6 + 3) necrotic damage, the undead spiked horror regains 10 hit points, and the target’s hit point maximum is reduced by an amount equal to the necrotic damage taken. This reduction lasts until the target finishes a long rest. The target dies if its hit point maximum is reduced to 0.