Harvey Kneeslapper

Harvey Kneeslapper appeared on Sesame Street as a mad practical joker, always pulling pranks on others. Usually, his pranks involved either letters or numbers, which he would slap onto his victims (who were often made from Fat Blue Anything Muppets; one of these was a look-alike, and sound-alike, for Mr. Johnson). In most of his skits, his pranks succeeded, much to the annoyance of his dupes. However, on rare occasions, Harvey's pranks backfired on him. Such instances usually occurred in skits where he explained his prank in advance to the audience.

He once appeared in a Sesame Street News Flash sketch, where he made a prank call about somebody standing out in a snowstorm.

Eventually, his raucous laugh became too hard on Frank Oz's throat, and Harvey, who was always considered a one-joke character, was dropped from the show. Even after Harvey stopped appearing in new segments, his existing segments continued to be used in new episodes up until Season 32.

Harvey later made a cameo appearance in a 2010 episode (performed by Matt Vogel), where he slaps a "7" on Wolfgang's beach ball. He also cameoed in the Letters CD-ROM game, pretending to be a shark in Ernie's tub.

Harvey Kneeslapper was the first character created by Norman Stiles.