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