She was dropped off in the Day Camp Area by Blythe. She meets the pets and gives off a nice scent. The pets love her scent and get excited around. She tells Zoe, Minka, and Penny that her signature scent makes everyone delirious. Minka asks her if she can make custom scents and she says yes. She can make any scent that anyone wants. They ask for a field with lilacs, orchids, and jasmines. She gives the scent to the girls and they enjoy it. The boys want to make a request to her. They ask for the beach with salt water, the sun, and a veggie dog. She gives the boys the scent and they enjoy it a lot. She sees Pepper walk away and feels sorry for her.
When Pepper wants to tell another joke, the pets reluctantly stay and Mitzi walks away. The pets walk away to ask Mitzi if she can make smell fresh, ignoring Pepper. Pepper gets really mad and gives off a bad smell. The pets choke on stink and beg Mitzi for a nice scent. Mitzi looks at Pepper being sad, feeling bad for her. The pets pleadingly ask her another scent to be happy and she reluctantly gives them one. She says it's Georgia Peach. She talks Pepper and she says envies her. She's about to say why when Pepper asks, but the pets demand more scents.
Mitzi stumbles into Pepper and tells her how much she envy's her. Pepper is confused and asks why. When she is about to explain, Penny interrupts and begs for more scents, as the pets chant "WE WANT MORE!". The two sing a song, and Pepper understands how she feels. She then runs off, feeling pressured by Minka. The pets suggest that she makes "color scents", but it gets overshadowed by Pepper's scent as she tries to prove a point. The pets walk away and Pepper explains how she releases her skunk emotions.
Zoe kindly reminds her about what she was going to do, but Mitzi proudly rejects and gives a bad smell. She announces that she is officially taking a break from taking pet's requests. After the pets, most noticeably Russell apologizes, Mitzi accepts. While talking to Pepper, she lets out a Rose Garden, but Pepper says it's not finished yet without some Peppermint mixed in.
Mitzi is friendly and polite. When overwhelmed, she becomes worried and tired in denial. She likes making people happy, to the point where she isn't making herself happy.
- She is voiced by Ashleigh Ball, who also voices Rainbow Dash, Applejack, and Blythe Baxter.
- Mitzi will meet Thomas, Twilight, and their friends in Thomas and Twilight Sparkle's Adventures of Littlest Pet Shop: Sue Syndrome
- Mitzi made her first appearance in and met our heroes again in Return to Paradise Falls.
- Mitzi is also the aunt-in-law of Rebecca.