The Dawnguard Add-on for The Elder Scrolls V: Skyrim has 10 achievements.
Complete "Kindred Judgment"
Learn all three words of Soul Tear
Complete "Beyond Death"
Complete "Awakening"
Complete "Lost to the Ages"
Use the special power of Auriel's Bow
Acquire 11 werewolf perks
Acquire 11 vampire perks
Change your face
Defeat a Legendary Dragon