Rowlf the Dog was the first Muppet to reach national stardom as a cast member of The Jimmy Dean Show from 1963 to 1966. He later went on to serve as the resident piano player on The Muppet Show, also playing the silly surgeon Dr. Bob on the recurring sketch "Veterinarian's Hospital".

Rowlf first appeared in 1962 in a series of Purina Dog Chow commercials. He was paired with Baskerville the Hound in a series of ads which aired from 1962 to 1963. Rowlf also appeared in an ad for Esskay Meats during the same time period.

Rowlf was the first Muppet built by Don Sahlin. Unlike most of the early Muppets, he was designed as a live-hand Muppet; he was also one of the first non-abstract Muppet characters, built to resemble a dog. According to Henson's original notes, other names considered for the character were Barkley, Woofington, Baskerville, Barkus, Howlington, Waggington and Beowolf. Jim Henson designed three different dogs, one of which became the design for Rowlf, and another of which became the design for Baskerville.

Rowlf rose to stardom as Jimmy Dean's sidekick on The Jimmy Dean Show. The show ran from 1963 until 1966. Rowlf the Dog was a regular on the show, and was billed as Jimmy's "ol' buddy." Between seven and ten minutes of every show were devoted to a spot with Rowlf and Dean. Many of the comedy sketches ended with the two singing a duet together. Rowlf's tenure on The Jimmy Dean Show allowed Jim Henson to develop the character over a period of time.

Rowlf continued to star on variety shows, hosting Our Place and appearing in several episodes of The Mike Douglas Show. He also hosted the 1968 special Muppets On Puppets.

Rowlf appeared in the 1965 Wilson's Meats Meeting Film, as an example of the Muppets' exposure ("I'm the Muppets' big lovable shaggy dog Rowlf, from ABC's The Jimmy Dean Show!"). He did a similar thing by "stopping by to say 'Howdy'" in the 1966 La Choy Chow Mein Presentation Reel.

He also appeared in the Sesame Street pitch reel, explaining the concept and production process to a wary Kermit, as both characters were the most familiar Muppets at the time. He also appeared in Sesame Street's first season, making a cameo appearance in the "Song of Nine."

Rowlf appeared in brief celebrity cameo-esque roles in the two Muppet Show pilots, The Muppets Valentine Show and Sex and Violence.

When The Muppet Show debuted, Rowlf was a part of the cast. Rowlf was assigned the role of resident pianist (abandoning his ukulele skills from The Jimmy Dean Show). At the piano, Rowlf would often perform classical music, and sing solos or duets. Rowlf also performed in the pit orchestra and sometimes sat in with the Electric Mayhem. Despite Rowlf's established fame among American audiences, a majority of his musical numbers were not seen in the US, as the sketches and songs starring Rowlf dominated the list of UK Spots.

Apart from displaying his musical talents, Rowlf continued his comedic style from The Jimmy Dean Show with his customary puns and gags – most notably as Dr. Bob, "the quack who has gone to the dogs," in Veterinarian's Hospital, or with a female partner in the recurring At the Dance segments. During the first season, Rowlf also appeared in two Poetry segments. Rowlf would occasionally take on other character roles in the on-stage productions - including Sherlock Holmes and a Western bar piano player. Whether in featured roles or non-speaking cameos, Rowlf appeared in 89 of the 120 episodes of The Muppet Show.

Due to Rowlf's musical skill, it is sometimes incorrectly assumed that he was a part-time member of The Electric Mayhem Band. Although Rowlf played in the orchestra and back-up on several numbers with musicians in the Mayhem band, Rowlf only accompanied the Electric Mayhem three times: in episode 424, in episode 513 and at Fozziwig's Christmas party in The Muppet Christmas Carol. In fact, when the Electric Mayhem walked out over the apparent lameness of The Muppet Show theme song in episode 123, Rowlf was the only musician left. As a result, Rowlf had to play the closing theme single handedly.

In 1985, Rowlf hosted two hour-long video compilations of The Muppet Show. In Rowlf's Rhapsodies with the Muppets, Rowlf sat at his piano and presented a compilation of his best numbers and other songs from The Muppet Show. In Country Music with the Muppets, Rowlf rented a barn and hosted his own country music program while showing clips from the show.