Muppet Time! This is labelled as an IBM training video but it's actually a performance on The Ed Sullivan Show from October '67 of material that Mr. Henson and his crew had earlier developed for an IBM in-house project called The Coffee Break Machine. It features an early version of the character who would later lose his teeth — though not his appetite for consuming things — and become famous as Cookie Monster.
The creature went through a number of incarnations. He was originally called The Wheel-Stealer because, I guess, in his first appearance he stole wheels. He was later in a series of commercials for a potato snack called Munchos and in those, he was Arnold the Munching Monster. Eventually, he found his true identity on Sesame Street.
I believe Jim Henson is performing the character here, probably with Frank Oz — who would later become the Cookie Monster we know and love — working at least one of the hands. The voice of the computer is Henson's so he probably pre-taped that. Listen to some of the double-talk from the computer because it's really quite funny, especially the Mome Raths…
