In the Superman comic books, Bizarro is an imperfect copy of the Man of Steel. He has pale, faceted skin and wears a backwards "S" on his costume. He always speaks in the third person, he's dumb as a post, and his grasp of grammar is very poor, so he tends to say things like "Bizarro am not a enemy of Superman! Bizarro am Superman's bestest friend!"

In the old "pre-Crisis" DC Universe, Bizarro was introduced in a 1958 "Superboy" comic. The perversely backwards villain was a hit with fans, and he was soon moved up into Superman's regular rogue's gallery. Bizarro had his own planet he lived on called Htrae, which was a cube. There, just about everyone looked like Bizarro Superman and Bizarro Lois Lane (The original Bizarro wore a sign around his neck identifying him as "Bizarro #1"). A Bizarro's thought processes are totally backwards -- someone can be sent to jail for doing good deeds, and "You am ugly cow, Bizarro Lois!" is considered a high compliment (and an indicator that someone's about to get some Bizarro Nookie).

In the "post-Crisis" universe, Bizarro was a creation of Lex Luthor. Designed to be a clone of Superman, he turned out to have a flaw that caused his body and mind to degenerate. Though he's been killed multiple times, he makes frequent returns, either as another imperfect clone or as a magically generated duplicate of the Man of Steel.

The word "Bizarro" has come to mean, in pop culture, anything that seems to be a strangely backwards copy of something else. There was an episode of "Seinfeld" where Elaine met people who looked similar to Jerry, George, and Kramer, but who had stable jobs, nice personalities, and healthy relationships. They were referred to as Bizarro Jerry, Bizarro George, and Bizarro Kramer. And in an episode of the "Sealab 2021" cartoon, the crew was tormented by Bizarros, who looked sorta like the original crew members, but wore black leather, had weird cybernetic or genetic alterations, acted even weirder than the regular crew, and liked to say "Bizarro!" over and over and over.
Also, Bizarro is a popular and very odd comic strip created by Dan Piraro. Started in 1985 to replace Gary Larson's "The Far Side" at Chronicle Features after Larson moved his comic to Universal Press Syndicate, the strip features surreal situations, lush artwork, and completely weird humor. Piraro's work on the strip has earned him the National Cartoonists' Society's award for the Best Newspaper Cartoon Panel in 200, 2001, and 2002.

Piraro hides tiny images of pies, firecrackers, bunnies, flying saucers, and more in almost every cartoon he draws.