When Ernst Stavros Grouper purchased the company that owns KMUP in episode 205 of Muppets Tonight, he insisted on making a few changes around the set. One of these changes involved Kermit the Frog's metamorphosis into Virgil the Monkey because "focus groups love monkeys more than frogs."
Virgil's humilation at the fins of Grouper pushed him to quit his job with the Muppets. He soon found himself in line at an unemployment agency (behind Bill Barretta), where Fred Willard informed him that there were no longer any network jobs available and the "dubba-dubba-dubba-WB" already has a frog and has no need for a monkey.
Virgil temporarily found work as a bartender at the bar where Statler and Waldorf sat watching Muppets Tonight.
Later, Virgil was hired back by Grouper, although he couldn't return until he finished his shift as Don Rickles' dancing monkey.