Cerberurian Horror

Corrupted Blood. When the horror takes piercing or slashing damage, each creature within 5 feet of the horror takes 5 (1d8) necrotic damage.

Antimagic Cone. The horror's central eye creates an area of antimagic, as in the antimagic field spell, in a 60-foot-cone. At the start of each of its turns, the horror decides which way the cone faces and whether the cone is active. The area works against the horror's own eye rays.

Multiple Heads. The horror has 3 heads. While it has more than one head, the horror has advantage on saving throws against being blinded, charmed, deafened, frightened, stunned, or knocked unconscious. Whenever the horror takes 60 or more damage in a single turn, one of its heads dies. At the end of its turn, it begins healing any heads that died since its last turn, unless it has taken acid damage since its last turn. The horror regains 5 hit points for each head healed in this way.

Reactive Heads. For each head the horror has beyond one, it gets an extra reaction that can be used only for opportunity attacks.

Wakeful. While the horror sleeps, at least one of its heads is awake.

Multiattack. The horror makes as many bite attacks as it has heads.

Bite. Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 17 (2d10 + 4) piercing damage.

Eye Rays. The horror shoots one of each of the following eye rays at two targets of it's choice within 60 feet of it.

1. Paralyzing Ray. The targeted creature must succeed on a DC 16 Constitution saving throw or be paralyzed for 1 minute. The target can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.
2. Sleep Ray. The targeted creature must succeed on a DC 16 Wisdom saving throw or fall asleep and remain unconscious for 1 minute. The target awakens if it takes damage or another creature takes an action to wake it. This ray has no effect on constructs and undead.