Muffy Peprich was the villain in the episode "Evil Sorority", in which she tried brainwashing the pledges of her fake sorority, Phi Epsilon Phi (or "PEP" short), along with all the other sororities at Malibu University.
In "Evil Sorority", she revealed that she was doing it to get revenge for being rejected from every sorority she had pledged to when she entered Malibu University, but she was later defeated and imprisoned.
Her appearance was similar to that of a punk rocker of the 1980s.
- DEBS (possibly acronym for Delta Epsilon Beta Sigma) members
- Gamma Alpha Gamma members
- Sigma Alpha Sigma members
- She makes a cameo in "Totally Spies! The Movie".
- Ziggy and Muffy Peprich both wear punk make-up. Ziggy has a purple star over his left eye (Muffy has a blue star over her right eye) like Paul Stanley of the rock band Kiss, who has a black star over his right eye.
- Muffy's voice actress is Megan Fahlenbock who also voiced Jen Masterson in 6teen and Gwen from the Total Drama franchise.