Here is the full list of all 13 DeathSpank: Thongs of Virtue achievements.
Discover all 44 Teleporting Outhouses
Kill the Taking Tree
Watch Both Game Endings
Kill Santa Claus
Go Sailing in a Pirate Ship
Reach Level 20
Kill Wortten
Learn to Speak Japanese
Get an Engineering Degree
See all 20 of Madame Primp's Outfits
Kill the Evil Nun
Convince an Orque Guard you are an Orque
Kill 3000 Enemies