Ernest Pleth is the host of "Wall Street Wonderings", whose program is interrupted by Spamela Hamderson in a bikini on Muppets Tonight episode 107, in an attempt to boost the station's ratings and prevent a bomb detonation. His staid life as a middle-aged stock analyst is suddenly upended, as Spamela's gyrations release his inhibitions, and Ernest joins her in rhapsodic dance movements, Though Spamela soon tires, Ernest continues solo, as the repressed sense of youth and vitality lurking beneath his bespectacled exterior has bubbled over, causing a spontaneous strip. This continues when he urges guest star Sandra Bullock to "take it all off."
Ernest re-appeared, apparently returned to middle-class normality, as a librarian in a "Thor, God of Thunder" sketch from episode 108, where he was performed by Dave Goelz. Pleth is vaporized by Thor and Zeus, and Nigel directs the crew to sweep up Ernest.