Half-man, half-vampire, the dhampir can fill any number of roles in your campaign: hero (likely tragic or anti-), villain, foil, informant with a secret, or convenient deus ex machina. And the dhampir as vampire slayer is so common in fiction and film as to be cliché by now (though don’t let that stop you—a cliché artfully employed is just a useful trope). Like other half-breed characters, dhampirs stand at the intersection of two worlds—and PCs encountering dhampirs should be made aware that one of those worlds wants to tear out their throats.
The albino Cervus Malfio has been sickly since birth, a pale creature too dazzled by sunlight to even go outside on bright days. On his seventeenth birthday, the day that was to be his confirmation, he was run down by a cart outside the temple just before the ceremony. This set off an inexorable chain of events: the priest rushing outside to apply cure light wounds, the spell sending the boy nearly to his death, word spreading of the ill magicks it took to save him, and finally the arrival of his father, ready to claim Cervus as his heir…and more than a few lives in the process.
The alleys of Greenwald are abuzz with rumors about a new thieves’ guild. This would have been inconceivable only a few years ago, in a land where vampires rule the underworld more or less openly. But the new guildmaster seems unafraid of both the living and the undead—he has beheaded his few mortal rivals, and seems to have enough influence (or leverage) over Greenwald’s vampires that they do not dare to do him harm.
Twicehome is a growing mountain town that is fast becoming known as a settlement where half-breeds of any kind are welcome—half-elves in particular, but also half-orcs, aasimars, tieflings, even the rare mongrelman. But the secret rulers of Twicehome are the dhampirs, whose holdings delve deep into the mountain. Without seeming to, they share power over almost every aspect of daily life in Twicehome…and they may share a common forbear as well.
—Pathfinder Bestiary 2 89