Related Clues:

• Heavy
• Villain
• One to root against
• The Joker in Batman movies, e.g.
• Villain of a piece
• Villain that might create problem in camp
• Action film foil
• Villain in an old movie
• Hit song by the 1-Across winner whose name is spelled out by the final three letters of 21-, 25-, 47- and 52-Across