Mitzi is one of Charlie's many one-night stands.
She appears in the first scene of "Media Room Slash Dungeon" as the woman who dated Charlie. When Evelyn arrived at home and asked Alan and Charlie if they would go with her to party, Charlie made excused himself that he has other plans with Mitzi. But after he saw her vomit after a kiss, Charlie agreed to go with Evelyn but to call a taxi because he wouldn't be sober.
- She's thinks Charlie's name is "Steve".
- For some reason, she vomits uncontrollably in the kitchen sink, right in front of the Harper family.