Mad Moxxi is an NPC mission provider. She is the hostess of the Colosseum matches in The Underdome in Mad Moxxi's Underdome Riot, and the owner of various bars on Pandora.

Moxxi could be summed up with the words sadistic, lustful, alluring, and dangerous. She enjoys violence and combat, having been a skilled fighter in her earlier years. Modesty has little to do with Moxxi, especially when it comes to sex. Her affairs are innumerable and she has had several husbands, and her lovers have been both male and female. She is also surprisingly refined in her tastes and mannerisms, always speaking with a seductive tone and an innuendo soon following.

Moxxi, despite her violent tastes, is also friendly and rather compassionate when fighting is not involved. She is a caring mother, in her own Pandoran way, and can be protective of her children and others close.