Inspired by [PJRZ's comment](https://rpg.stackexchange.com/questions/129231/can-a-creature-be-brought-to-consciousness-while-they-have-a-max-hp-of-0#comment320802_129239) on [this answer](https://rpg.stackexchange.com/a/129239/35259) to [this question](https://rpg.stackexchange.com/q/129231/35259):

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> What attacks actually exist that reduce someone's max HP, but do not specifically state what happens at max HP of 0?
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As far as I am aware, all monster abilities that can reduce max HP to 0 state that the creature dies (and optionally may be brought back as some undead creature, depending on the exact creature/attack used to reduce the max HP to 0).

As an example of an attack that *does* state what happens, consider a [Wraith's](https://www.dndbeyond.com/monsters/wraith) ***Life Drain*** attack (MM, pg. 302):

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> ***Life Drain.*** *Melee Weapon Attack*: +6 to hit, reach 5 ft., one creature. *Hit*: 21 (4d8 + 3) necrotic damage. The target must succeed on a DC 14 Constitution saving throw or its hit point maximum is reduced by an amount equal to the damage taken. This reduction lasts until the target finishes a long rest. **The target dies if this effect reduces its hit point maximum to 0**.
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**Are there any attacks or effect that reduce a creature's max HP to 0, but do not address whether or not the target dies?**