Wiktionary
interj. Nonce variation of the word bump, usually indicating the sound of someone or something tumbling down an uneven surface, or traveling on a rough road.
Wikipedia
Bumpity was an American children's television show that aired locally in the Portland, Oregon area on the ABC affiliate KATU, from 1971 to 1985. Bumpity, a green "bump on a lawn" with one pronounced tooth, along with his friend and side-kick, a red and purple striped worm named Fred, hosted the show. Other friends included Digger Mole and Scotty MacThistle. Fred never said a word, but did make squeaks in what he termed "High Worm".
An employee of the station named Bob Griggs, came up with an idea to design a puppet as an answer to a call from the Federal Communications Commission (FCC) which had asked local station affiliates around the country to air family friendly and educational morning programming. Bob created the characters with less than three dollars. The concept was approved and quickly became a hit with kids and parents alike due the program's easy, gentle nature.
Bumpity's most frequent guests to "Bumpity Park" included the librarians from the Multnomah County Library, who would bring children's books to read. Other times Bumpity welcomed police officers, dentists, clog dancers, and magicians.
In 2001 Crispin and Patrick Rosenkranz created a short documentary about Bumpity titled "Bumpity Returns." The video is available through their website or can be checked out from the Multnomah County Library. The documentary includes interviews with Bob Griggs and others involved with the program, and with Bumpity himself, and also features clips from the show.
Usage examples of "bumpity".
I heard the muffled bong of the corridor call bell, a night shriek of city brakes, the thunder-roll of a jet, fast and high, and soon the more immediate bumpity-thud, bumpity-thud of Mrs.
Anyhow, all of a sudden the White Horse toppled right over on top of the bad burglar, and down the stairs they went, bumpity-bump!
But they brought him to the Fair, Now upon his hump, Every child can take a ride, Who can stand the bumpity-bump.
They rolled them bumpity-bump down the cellar stairs, and began filling them with potatoes as fast as they could.