From Disney's Hollywood Studios Wiki
Fozzie Bear is The Muppet Show's resident comedian. He's an orange-brown, fuzzy Muppet bear who tells bad jokes, usually punctuated with his catchphrase, "Wocka wocka wocka!" He also often says "AaaAAAAaaah" when he tells the jokes, which somewhat serves the same purpose as "Wocka wocka." Fozzie is also best friends with Kermit the Frog, although they occasionally have differences of opinion.
 Studios Reference
 Early Appearances
During the first season of The Muppet Show, Fozzie's monologues usually consisted of Fozzie telling simple setup/punchline jokes, while being heckled by his mother's old friends, Statler and Waldorf. After the first season, most of his monologues relied on gimmicks such as telling jokes on roller skates. A common schtick in many episodes is that Fozzie would attempt to imitate the guest star's most famous act to attempt to emulate their success, only to comically fail completely at the attempt. For instance, Edgar Bergen inspired him to try ventriloquism while stage magician Doug Henning inadvertently convinced Fozzie to try his hand at being a magician. Fozzie also told a joke during the opening sequence of every episode during the first season.
 Later Appearances
Fozzie Bear only appeared in a handful of episodes of The Jim Henson Hour. One of his most notable appearances was in the Monster Telethon episode, in which Fozzie decided to give up comedy and become a weather bear. He went to the set of The Today Show to get some tips from the show's weather man, Willard Scott, only to inadvertently lock Scott in a closet. With Scott locked in the closet, Fozzie came on-stage to report the weather, but had trouble reporting, and went back to comedy.
During the early 1990s, Fozzie appeared less frequently, usually in supporting roles and often wearing a wig. In The Muppet Christmas Carol, he made a cameo appearance as Scrooge's employer Fozziwig. Shortly afterwards, he appeared in one sketch in Muppet Classic Theater, portraying the title character in The Emperor's New Clothes.
In Muppet Treasure Island, he had a more substantial role as Squire Trelawney, who financed the voyage and hired the crew, based on Long John Silver's suggestions. In this movie, Fozzie's character referred to and often spoke to a tiny man named Mr. Bimbo, who lived inside his finger.
On Muppets Tonight, Fozzie made quite a few appearances, but was less integral to the series, with most of his appearances being in sketch roles. He appeared with Kermit and Billy Crystal in a sketch called City Schtickers, with John Goodman and Miss Piggy in a Honeymooners parody called The Lunar Mooners, and in a recurring sketch called EIEIO-R, portraying a doctor who told jokes, similar to Rowlf's role as Dr. Bob. Fozzie's only backstage appearances were in episode 109, in which he watched one of Whoopi Goldberg's acts and wrote down some of her jokes, and in episode 204 where he helped cheer up guest star Pierce Brosnan.
 Back in the Spotlight
Fozzie became more of a major character again in Muppets from Space. He was part of the main cast and was the one who drove the Electric Mayhem Bus. He also got to work with Kermit again, reviving a pairing which had been absent for most of the 1990s.
He was also a major presence in It's a Very Merry Muppet Christmas Movie, which was Eric Jacobson's first major performance as Fozzie. Unlike many of his 1990s appearances, in which Fozzie was written as a rather dim-witted bear, he was depicted as more intelligent again, with humor coming from his devotion to the other Muppets. When Pepe the King Prawn revealed that Rachel Bitterman changed the contract for payment of the Muppet Theater, Fozzie chose to cancel his big Christmas monologue in order to hand-deliver a payment, in an attempt to save the theater. Later in the film, when Kermit saw what life would have been like if he hadn't been born, it was revealed that the Fozzie Bear of the Kermit-free world would've become a pickpocket.
Shortly afterwards, Fozzie would have a major role as The Cowardly Lion in The Muppets Wizard of Oz, and he got his own track, "North Pole Comedy Club", in A Green and Red Christmas.
 Fozzie and Kermit
Since the early days of The Muppet Show, Fozzie has often interacted with Kermit. Fozzie got Kermit to reluctantly assist him for one of his best-known monologues, "Good Grief! The Comedian's a Bear!", and has also had quite a bit of interaction with Kermit backstage.
Kermit and Fozzie have also frequently been paired together in countless movies, books, and specials. In The Muppet Movie, Fozzie was the first Muppet Kermit met on his journey. After Fozzie's unsuccessful comedy performance at the El Sleezo Cafe, Kermit invited Fozzie to come to Hollywood with him. The two friends sang the duet "Movin' Right Along" in the same film.
 Fozzie and Rowlf
Fozzie was also frequently teamed up with Rowlf the Dog. In episode 101, Fozzie played a western bandit to Rowlf's role as a western hero. In episode 218, Rowlf learned that Fozzie could play the piano (a talent Fozzie didn't know about either), and they played the piano together in a performance of "English Country Garden". Rowlf has also played back-up to Fozzie's renditions of "Hi-Diddle-Dee-Dee (An Actor's Life for Me)" and "I've Got Rhythm." During the latter number, Rowlf attempted to help Fozzie with his singing.
The young incarnations of Fozzie and Rowlf were also frequently paired together on Muppet Babies.
 Working For Fozzie
Fozzie's agent, introduced in episode 122 of The Muppet Show, is Irving Bizarre, who is so short that his top hat covers most of his body. Fozzie also has a hired writer, Gags Beasley, who was first mentioned in Episode 114. Fozzie and Gags have a deal, whereby Fozzie pays his writer by the laugh. According to Frank Oz, "[Fozzie] can't afford good joke writers, and he can't write good jokes himself."
 Other Talents
Although Fozzie's main job on The Muppet Show is to be the stand-up comedian, he takes on the occasional dramatic role, and often assists backstage. He appears in sketches with guest stars Avery Schreiber and Nancy Walker, and he also appears in the recurring sketch Bear on Patrol.
In episode 201, Kermit let Fozzie help plan the show. His abilities in doing so earned him the title of "Honorary Hip Dude" from the Electric Mayhem band. Sadly, his planning also later lost him that title. Then, when Kermit becomes sick in episode 206, Fozzie is put in charge of hosting the show, which proves quite taxing for the bear.
Fozzie had also made an attempt to write for the show in episode 314 when he decided that the show needed a script. Unfortunately, Fozzie is either a bad speller or a bad typist (or both), as Kermit found it difficult to read the introductions that Fozzie wrote for him. Fozzie later admitted that he was a bad speller when he wrote the word "Muffets" as part of the title card for The Muppets Go to the Movies.
 Performing Fozzie
In the two pilot episodes of The Muppet Show Fozzie had a mechanism which allowed his cheeks to move. During the remainder of the first season, Fozzie was a bit more plump, and had ears that wiggled.
Fozzie was rebuilt for the second season of The Muppet Show; he was given a brighter orange hue, a tighter overall design, and a less "dopey" appearance. A special mechanism allowed his eyebrows to move, but the effect was barely noticeable, especially when he wore his hat. This eyebrow feature was removed when he was replaced with yet another puppet, just seven episodes into the second season.
 Behind the Scenes
In Jim Henson: The Works, Christopher Finch wrote: "One of the biggest problems [with the first season] was with Fozzie Bear. Fozzie was crucial to The Muppet Show because he was conceived as Frank Oz's main character, and the success of the show would depend to a significant degree on Frank having the opportunity to display the full range of his virtuoso performance and comedic skills.
It was logical to have a comedian as a primary character on The Muppet Show, particularly once the Muppet Theater had been established as its basic setting. And given the spirit of the Muppets, it was almost inevitable that he would be a bad comedian. The problem with Fozzie was that his bad jokes and failure to win over an audience provoked more embarrassment than sympathy. For instance in episode 122, Fozzie gets so fed up with the heckling that he demands everyone but true Fozzie fans leave the auditorium. As a result, the seats are left completely empty; even Fozzie's own cousin leaves; Fozzie departs the stage almost in tears."
Jerry Juhl and Frank Oz gradually transformed Fozzie by building up the positive aspects of his personality. They allowed his perpetual optimism to offset his onstage failures until he became a more rounded character. Fozzie's virtues ultimately made his ineptness acceptable -- and even endearing. So successful was this metamorphosis that he became one of the most popular of all the Muppets."
As Brian Henson notes in a generic Muppet Show introduction, "Fozzie is always telling terrible jokes, but he's just trying so hard you've got to love him."