As an action, you can make a melee weapon attack with a natural weapon that deals piercing or slashing damage in an attempt to cause jagged wounds that bleed. Add the stamina die to the attack’s damage (add half if you miss by 4 or less). On a hit, the creature is bleeding for the duration.
At the start of each of its turns while bleeding, the creature must succeed on a Fortitude saving throw or it loses health equal to the stamina die. On a success, the effect end.
If the creature regains health while bleeding, the bleeding ends.
This has no effect on any creature that cannot bleed or lose a vital liquid substance.
You can increase the damage for each additional stamina die expended.