From Wikipedia:
Gumby is an American clay animation franchise, centered on a green clay humanoid character created and modeled by Art Clokey. The character has been the subject of two television series as well as a feature-length film and other media. Since the original series' run, he has become well known as an example of stop motion clay animation and an influential cultural icon, spawning many tributes, parodies, and merchandising.
Gumby follows the titular character and his adventures through different environments and times in history. Gumby's principal sidekick is Pokey, a talking orange pony. His nemeses are the Blockheads, a pair of humanoid, red-colored figures with cube-shaped heads, who wreak mischief and havoc. The Blockheads were inspired by The Katzenjammer Kids, who were always getting into scrapes and causing discomfort to others. Other characters are Prickle, a yellow dinosaur who sometimes styles himself as a detective with pipe and deerstalker hat like Sherlock Holmes, and Goo, a flying blue mermaid who spits blue goo balls and can change shape at will. Also featured are Gumby's dog Nopey, whose entire vocabulary is the word "nope," and Gumby's parents, Gumbo and Gumba. The later syndicated series in 1987 added Gumby's sister Minga and mastodon friend Denali.
Gumby was created by Art Clokey in the early 1950s after he finished film school at the University of Southern California. Clokey's first animated film was a 1953 three-minute student film 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 Clokey's professor Slavko Vorkapić taught at USC 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 animating figures into children's stories.
Clokey moved forward producing a pilot featuring the character Gumby, which derived its name from the muddy clay found at Clokey's grandparents' farm that his family referred to as "gumbo". The look of Gumby was inspired by a suggestion from his then-wife Ruth (née Parkander) that Clokey base his character on The Gingerbread Man. The color green was then chosen because Clokey saw it as a racially neutral color, as well as being a symbol of life. 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 Charles Farrington in an old photograph.
NBC executive Thomas Warren Sarnoff saw and loved Clokey's first pilot and had Clokey make another one ("Gumby on the Moon"). This became a huge hit on Howdy Doody, leading Sarnoff to order Gumby his own series in 1955 entitled The Gumby Show. In 1955 and 1956, 22 eleven-minute episodes aired on NBC. Gumby's voice was originally provided by Ruth Eggleston, wife of the show's art director Al Eggleston, until Dallas McKennon became the primary voice of Gumby in 1957. Because of its variety-type format, the show not only featured Clokey's puppet films but interviews and games as well. During this time, the show went through a succession of two hosts: Robert Nicholson ("Nick") and Pinky Lee.
In 1959, the show entered syndication and more episodes were later produced in the 1960s. Production continued through 1968, by which time Norma MacMillan voiced Gumby. On some occasions during this time, Gumby's voice was provided by Ginny Tyler and Dick Beals.