From Wikipedia:

Gumby is a green clay humanoid figure who was the subject of 233 episodes of American television which spanned over a 35-year period. He was animated using stop motion clay animation. Created by Art Clokey, the Gumby episode, Robot Rumpus, made a successful debut on the Howdy Doody Show in August 1956, and in 1957 Gumby was given his own NBC series.

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.

Gumby's principal sidekick is Pokey, a talking pony, and his nemeses are the Blockheads. Other characters are Gumby's dog Nopey (who responds to everything with a gloomy "nope"); Prickle, a yellow dinosaur or dragon; Goo, a flying blue mermaid who spits blue goo-balls; Gumby's mother Gumba; Gumby's father Gumbo; his sister Minga; Denali (a mastodon); Tilly (a hen); King Ott; and Professor Kapp.