Raised by Dwarves

NPC-Only feat (do not select on PCs):

You were raised by dwarves like one of their own, and have significantly bolstered your constitution as a result. Your hit point maximum increases by an amount equal to twice your level when you gain this feat. Whenever you gain a level thereafter, your hit point maximum increases by an additional 2 hit points. Furthermore, you have advantage on saving throws against poison, and you have resistance against poison damage.