Vanity

Aren't you just perfectly, wonderfully, beautifully gorgeous? You can't pass a mirror without admiring your looks. Or maybe doing a quick check whether something's stuck in your teeth, perhaps?

Obtainable by using Wall Mirrors 300 times. Note that getting the message Don't be so vain does not count towards the achievement, which is why being drunk in order to eliminate the possibility of this message appearing will save a lot of time. Also note that it is impossible to gain this achievement through the use of wall mirrors that spawn as objects in-game, such as the one above the Swamp Troll Cave near Venore.