Arthur "Fonzie" Fonzarelli was the extremely
cool ulta-hip biker on the TV show Happy Days.
Fonzie was originally meant as a one time walk on, but became an instant sensation and was the meat of the show, but like Steve Urkel is to Family Matters. Fonzie was played by Henry Winkler and it is a role Winkler has been known by ever since.
Even though Fonzie is refered to by many as "cool", part of Fonzie's charm was that he had many characteristics that made him a nerd.
In Pulp Fiction we see characters refer to what Fonzie is... and Fonzie is cool.