Fifi is a minor animal character who has never appeared in the Peanuts comic strip but is featured in the animated TV special Life Is a Circus, Charlie Brown, as well as a supporting character in The Peanuts Movie, where her design is changed slightly. She is a white poodle with long black eyelashes and she wears a pink bow and collar. Fifi performs in a circus dog act called "Miss Polly and her Poodles" along with two other unnamed dogs.
In Life Is a Circus, Charlie Brown
Snoopy falls in love with Fifi at first sight. He follows her from a train wagon into a circus tent, at which point he is grabbed by Fifi's trainer, a girl named Polly, and made part of the act. Largely because he does not want to embarrass himself in front of Fifi, Snoopy picks up circus skills quickly. It is because he wants to protect Fifi that Snoopy ultimately rebels against Polly, attacking the girl and running away from her, when she tries to dye both dogs pink.
Fifi appears to have the same feelings for Snoopy which the beagle has for her. She encourages him to follow her at the beginning of the special and she kisses him several times. Fifi runs away from Polly with Snoopy and follows him to a bus stop. However, instead of getting on the bus home with Snoopy, Fifi ultimately decides to go back to the circus, leaving the beagle broken hearted.
In The Peanuts Movie
Fifi has a major role in the CGI film The Peanuts Movie, albeit with a new design and voiced by Kristin Chenoweth. In this film, Fifi appears in the scenes where Snoopy is imagining himself wooing her during World War I. She appears with features similar to a beagle but with pink poodle-like tufts on her ears, tail and head. In the World War I story, she is a pilot in her own right who flies a Sopwith Camel biplane. She is captured by the Red Baron and rescued from a dirigible by Snoopy and the Beagle Scouts.
Following Snoopy's victory over the Red Baron, she appears celebrating amongst Snoopy and his family in the movie's mid-credits scene.