From Muppet Wiki

Samuel Snively is a super shapes salesman for the Snidley Super Shapes Company of Saskatoon, Saskatchewan. The salesman solicits the sale of specialized shapes to citizens of Sesame Street, namely Bob, in a Sesame Street one-shot sketch.

Mr. Snively specializes in selling circles from his suitcase, stoping to show samples of his circle, includeing striped circles, sequined circles, and small circles. He tries, without success to sell Bob a three-sided circle (triangle) and a four-cornered circle (square).