False Potion (5e Equipment)
From D&D Wiki
This small glass bottle has illusion magic cast upon it making it appear to be full of a beneficial liquid such as the glimmering red liquid of a potion of healing. Even the identify spell is mislead by the illusion magic, causing the bottle to be identified as the potion it resembles. A character that spends time inspecting the potion can make a DC 20 Arcana check or a check with alchemist's supplies if applicable to reveal the true nature of the contents.
If a creature consumes the contents of the bottle, they must make a DC 15 Constitution saving throw. On a failed save, it takes 5 (2d4) poison damage and is poisoned for 1 hour. On a successful save, the creature takes half damage and isn't poisoned.