Gumby is a green clay humanoid figure who was the subject of a 233-episode series of American television which spanned over a 35-year period. He was animated using stop motion clay animation.
Gumby's principal sidekick is Pokey, a talking pony voiced by Art Clokey and Dallas McKennon at different times, and his nemeses are the Blockheads, a pair of humanoid, red-colored figures with block-shaped heads, who wreak mischief and havoc at all times. The Blockheads were inspired by the Katzenjammer Kids, who were always getting into scrapes and causing discomfort to others. Other characters are Gumby's dog Nopey (who responds to everything with a gloomy "nope"); Prickle, a yellow dinosaur or dragon, who often declares himself as a detective, sporting a pipe and a hat in the likeness of Sherlock Holmes; Goo, a flying blue mermaid who spits blue goo-balls and can change her physical shape at will; Gumby's mother Gumba; Gumby's father Gumbo; his sister Minga; Denali (a mastodon); Tilly (a hen); King Ott; and Professor Kapp.
Gumby was created by Art Clokey while a student of Slavko Vorkapich at the University of Southern California. Clokey and his wife, Ruth (née Ruth Parkander), invented Gumby in the early 1950s at their Covina home shortly after Art finished film school at USC. Clokey's first animated film was a 1953 three-minute short called Gumbasia, a surreal montage of moving and expanding lumps of clay set to music in a parody of Disney's Fantasia. Gumbasia was created in a style Vorkapich taught called Kinesthetic Film Principles. Described as "massaging of the eye cells", this technique of camera movements and editing was responsible for much of the Gumby look and feel. In 1955 Clokey showed Gumbasia to movie producer Sam Engel, who encouraged him to develop his technique by adding figures. Of the three pilot episodes of Gumby, the first was done by Clokey on his own, and the next two were done for NBC and shown on The Howdy Doody Show to test audience reaction. The second 15-minute pilot, "Gumby Goes to the Moon", was initially rejected by NBC executive Thomas Warren Sarnoff. The third Gumby episode, "Robot Rumpus", made a successful debut on the Howdy Doody Show in August 1956. Gumby was an NBC series starting in 1957. 
Gumby was inspired by a suggestion from Clokey's wife Ruth that he base his character on the Gingerbread man. Gumby was green simply because that was Clokey's favorite color. Gumby's legs and feet were made wide for pragmatic reasons: they ensured the clay character would stand up during stop-motion filming. The famous slanted shape of Gumby's head was based on the hair style of Clokey's father in an old photograph.
Female performers (among them Ginny Tyler and Nancy Wible) supplied Gumby's voice during the initial episodes. New episodes were added from 1961 to 1963, at which time Dallas McKennon became the voice of Gumby. Production continued through 1966-1968, by which time Norma MacMillan voiced Gumby.
By the 1980s, the original Gumby shorts had enjoyed a revival, both on television and home video. This led to a new incarnation of the series for television syndication by Lorimar-Telepictures in 1988 that included new characters such as Gumby's sister Minga, Tilly the chicken, and Denali the mastodon. Dallas McKennon returned as the voice of Gumby in new adventures that would take Gumby and his pals beyond their toyland-type setting and establish themselves as a rock band.
In addition to the new episodes, the classic 1955-59 and 1961-68 shorts were re-run as part of the series, but with newly recorded soundtracks, including new voices and synthesized musical scores (Clokey's rights to use the original Capitol Records production tracks could not be renewed at the time, due to legal issues.)
Art Clokey reportedly gave many movie industry talents their first break in the business. A number of the clay animators who worked on the new series went on to work for Pixar, Disney and other studios.