Penny Marshall
Garry Marshall, creator and then part-time writer for "Happy Days", cast Marshall and Cindy Williams to guest on an episode of the show. The installment, titled "A Date with Fonzie", aired on November 11, 1975 and introduced the characters Laverne DeFazio and Shirley Feeney (played by Marshall and Williams, respectively). In that episode, Laverne and Shirley were a pair of wisecracking brewery workers who were dates for Fonzie (Henry Winkler) and Richie (Ron Howard). The pair were such a hit with the studio audience that Garry Marshall decided to co-create and star them in a successful spinoff, "Laverne & Shirley" (1976–1983). The characters of Laverne and Shirley appeared in five more episodes of "Happy Days". In 1982 at the beginning of "Laverne & Shirley"s eighth season, Williams left the show due to her pregnancy. Marshall continued with the show, but it was canceled after the season's final episode aired in May 1983.
Suzi Quatro
Quatro is possibly best known in the United States for her role as the bass player Leather Tuscadero on the television show "Happy Days". The show's producer, Garry Marshall, had offered her the role without having an audition after seeing a photograph of her on his daughter's bedroom wall. Toby Mamis, who was acting as her U.S. representative at that time, helped effectuate the deal and generate enormous media attention to it, elevating Quattro's profile in her home country. Leather was the younger sister of Fonzie's girlfriend, hot-rod driver Pinky Tuscadero. Leather fronted a rock band joined by principal character Joanie Cunningham. The character returned in other cameo roles, including once for a date to a fraternity formal with Ralph Malph. Marshall offered Quatro a Leather Tuscadero spin-off, but she declined the offer, saying she did not want to be typecast.