Blue's Clues Season 3 Episode 18 Blue's Big Costume Party Episode Title:Blue's Big Costume Party.Episode Description: Today is Blue's Big Costume Party. Everyone is dressed up in all sorts of interesting costumes, but who is dressed up as what? We use our observation skills to figure it out. We also skiddoo into a haunted house and search for the mysterious Oogulah Boogulah. Later, everybody does the costume limbo, finding out just how low they go while dressed up in their costumes.