This perk allows you to regain health by consuming Bloodpacks.”— In-game description, Fallout 3
To obtain this perk, convince Vance to enter into a deal with the town of Arefu by passing a Speech check, a Medicine skill check, or an Intelligence check at the conclusion of the Blood Ties quest. Then return to Vance and ask to be shown the ways of the vampire.
Hematophage is definitely worth obtaining if you've completed Blood Ties by brokering a deal. Blood packs can occur randomly, especially in First Aid Kits, and are one of the few restorative items that aren't irradiated. Without the perk, they are relatively low-value items.
- Hematophagy "is the habit of certain animals of feeding on blood (from the Greek words, haima, blood and phagein - to eat)"
- If you finish Blood Ties by killing The Family then you won't be able to get this perk.
- If between finishing Blood Ties and attempting to get this perk, you kill anyone in Arefu or become hostile with Arefu or The Family, Vance will not teach you this perk, and call you an "asshole".