You have an iron stomach from consistently eating poisonous plants, rotten food, or potentially literal garbage. How you are still alive is a mystery to everyone, but your grizzled gut provides some benefits.

Gain advantage on saving throws involving poison. You can identify ingested poisons and potions by ingesting a small amount of them, and with a successful Nature check DC 10 for weak poisons and venoms, DC 14 for hand-crafted potions and toxins, and DC 18 for strong poisons and venoms. You can identify the specific ingredients in potions with a Medicine check DC 20.

Your gain proficiency with alchemist's supplies, poisoner's kit, and herbalism kit. If you are an Ooze race, your body now functions as all 3 of these.

You can craft potions and poisons you've both ingested and identified, as long as you possess the required materials to do so.