Viewers knew that the last-ever episode of the critically acclaimed 'Colbert Report' would be epic, but few could get exactly how epic.

Unless, of course, they were among the multitude of celebrities who filled the Comedy Central show's soundstage well past capacity last night (Dec. 18). An ever-growing number of musicians, athletes, actors, media personalities and politicians joined host Stephen Colbert in a rendition of "We'll Meet Again."

James Franco came out of his 'Interview' bunker to join in all the fun. Cyndi Lauper's colorful look complemented Big Bird and the Cookie Monster's. Former President Bill Clinton and an astronaut in outer space were among those making appearances via videotape. It's near impossible to name all of the special guests onstage, although this list comes close.

Colbert is ending his 10-year run as host of the political satire to take over for David Letterman on 'The Late Show.' Letterman's final episode is May 20, 2015; no date has yet been set for Colbert's debut.