You have fangs that allow you to drain the blood of your victims.
Prerequisites
Monstrous Bloodline (Vampire), bloodline level 1st.
Benefit
You gain the Fangs mutation and the Blood Hunger mutation drawback.
As a full-round action that does not provoke attacks of opportunity, you can make a bite attack and drain blood from an adjacent creature that is both living and either willing or helpless. Alternatively, you can drain blood from a creature that you have pinned in a grapple, in which case you do so instead of any other action when you successfully maintain the grapple. Either
way, this inflicts 1 point of Constitution damage on the target per round that you continue the attack (in addition to the 1d6 damage inflicted by your Blood Hunger mutation).
For every point of Constitution damage inflicted in this way, you gain a single blood point.
In addition, you gain a bloodcaster level equal to your bloodline level.