Jaraba rubber

This poison looks like a light gray rubbery paste. Mixed with food, it dissolves when cooked to become undetectable by taste or smell.
A creature subjected to this poison must succeed on a DC 16 Constitution saving throw or be poisoned. Also, while poisoned in this way, the creature's hit point maximum is reduced by 50%. The creature can make a new saving throw every minute (10 rounds) to end the effect and restore its hit point maximum (but not its current hit points). The DD decreases by 1 each time.