Armor of Kyuss

A protective magical force surrounds you, manifesting as collection of hideous worms that cover you and your gear. You gain 5 temporary hit points for the duration. If a creature hits you with a melee attack while you have these hit points, the creature takes 5 necrotic damage and a worm attempts to burrow into the target.

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, both the temporary hit points and the necrotic damage increase by 5 for each slot.

Burrowing Worm. A worm launches from the armor of Kyuss at the humanoid that hit you. The worm latches onto the target's skin unless the target succeeds on a DC 11 Dexterity saving throw. The worm is a Tiny undead with AC 6, 1 hit point, a 2 (-4) in every ability score, and a speed of 1 foot. While on the target's skin, the worm can be killed by normal means or scraped off using an action (the spawn can use this action to launch a scraped-off worm at a humanoid it can see within 10 feet of the worm). Otherwise, the worm burrows under the target's skin at the end of the target's next turn, dealing l piercing damage to it. At the end of each of its turns thereafter, the target takes 7 (2d6) necrotic damage per worm infesting it (maximum of 10d6). A worm-infested target dies if it drops to 0 hit points. If a worm-infested creature is targeted by an effect that cures disease or removes a curse, all the worms infesting it wither away.