The Fonz (formally Arthur Fonzarelli) is the star character from the 1974 sitcom "Happy Days" and was played by Henry Winkler. When his character was first introduced on the series, he wasn't meant to be the star character, but rather only to give the show a "bad" influence. As the show developed, he got more and more popularity until he finally became the hallmark character of that show. When most people think of Happy Days, they think of Fonzie in his trademark '50s greaser jacket. He is also very well known for his "Ayyy", and also for "jumping the shark" (literally, thus coining the phrase).
Fonzie has appeared in a few animutations but not very many. He seems yet to gain the kind of popularity in the animutation world that Colin Mochrie has. One might say that Colin Mochrie is to animutation as Fonzie is to Happy Days.