She first appeared in the episode "Oh Brother" when Fozzie shares the news that his family is adopting a little sister, and he is worried that he doesn't have what it takes to be a big brother. Fozzie's friends use their imaginations to enroll him into "Rizzo's Big Bruddah School." But when Rozzie arrives he is ready to take the job of a big brother to take care of her.
He first major appearance was in the episode "Fozzie's Boo Boo Patrol" on her first day going to the play group and Fozzie wants to make it the best day ever. But when Fozzie starts getting worried she doesn't have a good time, when she almost gets hurt jumping rope. So Fozzie starts the boo boo patrol watching Rozzie berry closely to make she doesn't get hurt and starts protecting Rozzie from doing anything and get into a fight. After, Fozzie gets angry and puts Rozzie in a boo boo time out. But when Fozzie get distracted with Animal, she escapes to get her toy truck. After, Fozzie sees she escape she comes afterher in his tricycle. But, Rozzie escapes in her tricycle and gets hurt. But when Fozzie realized what he's done. He apologized to Rozzie and continued playing. In the episode "The Copy Club" where she keeps copying Fozzie making it hard for him to practice for his Banana-mazing Juggling Joke show and gets accidentally cloned by Bunsen Honeydew and Beaker.