Fetid Cloud (1/Day). Constitution Saving Throw: DC 11, each creature in a 10-foot Emanation originating from the dretch. Failure: The target has the Poisoned condition until the end of its next turn. While Poisoned, the creature can take either an action or a Bonus Action on its turn, not both, and it can't take Reactions.
Condition immunities: poisoned. Senses: Darkvision 60 ft.; Passive Perception 9. Languages: Abyssal; telepathy 60 ft. (works only with creatures that understand Abyssal). Speed: 20 ft..
RollQuest ships the D&D 2024 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.