I want my mummy.

Marie is more than a simple criminal underlord.  She was killed nearly a century ago during a wild spree murder.  She wasn't simply murdered; she was dismembered by her husband and fellow jewel heister.

Because of a curse placed upon her by her dearly departed heinous-crime-committing husband, Marie shall live forever as a member of the Undead.  Having garnered herself amazing credentials during her living life, she has been elected Queen of the Undead Mafia in her after-life.  Thus, Reggie's Underlord.

Lucky for Reggie, Marie has many compatriots who are more than happy to help her out.  And that is how her secret treehouse came to be guarded by another member of the Undead: Mac the (Ninja) Mummy.