Bugs Bunny, the smart-aleck cartoon rabbit, known equally well for his carrots, his quips, and his trademark question—"Eh, what's up, Doc?"—is one of the most popular animated characters ever created.

The rascally rabbit's origins gave no hint of the greatness to come. He first appeared in Porky's Hare Hunt, a 1938 Warner Brothers cartoon. He was drawn smaller than he would later become and was also completely white. In his debut, Bugs was given no name; he was simply an unidentified rabbit who turned Porky Pig's hunting expedition into a farce.

The character's appearance and attitude evolved through several more cartoon appearances. Bugs Bunny finally reached the form for which he is best known in 1940's A Wild Hare. Directed by Tex Avery (1908–1980), this was the first cartoon to use the line "What's up, Doc?" The tall, gray-and-white rabbit remained unnamed.

That anonymity changed in...