Sneak peek at Charlie Sheen's impromptu appearance on GSN's "DREW CAREY’S IMPROV-A-GANZA" hosted by Drew Carey. The series will premiere on Monday, April 11, at 8:00 p.m. and 11:00 p.m. ET/PT on GSN.

Charlie Sheen will appear in the episode airing Tuesday, April 12, at 8:00 p.m. and 11:00 p.m. ET/PT.