Beltyn's burning blood

You infuse a living creature's blood with a hot, corrosive mixture, dealing 1d8 points of acid damage and 1d8 points of fire damage per round. Each round, on its action, the subject may attempt a Fortitude save to negate that round's damage, but a successful save in one round does not necessarily prevent damage in future rounds. On any round in which the subject fails its Fortitude save, the pain limits it to a single move-equivalent action in that round.

Beltyn's burning blood does not affect creatures of the construct, elemental, ooze, plant, or undead types.