Space Ghost is the host, his enemies Zorak and Brak are held prisoner and forced to help him on the show.
Zorak is somewhat restrained to his Prison Pod, Brak on the other hand is just sorta stuck at a table..

Instead of having guests on this show they had a mailbag, a Monday Ratings Report, and sang songs.
Which they somehow manage to make totally hilarious.

Unfortunately Cartoon Planet is no longer on Cartoon Network, although Space Ghost Coast To Coast and Brak Presents The Brak Show Starring Brak are.