Satan, AKA the devil, or Lucifer, or various other names, is a bad guy. Known to tempt Jesus Christ and other people in their hours of need, he's sometimes worshipped by fans of heavy metal and role-playing games. Apparently.
Actually the various names may be the names of various individuals lumped together into an archetypical bad guy image. 'Lucifer' was the name of the first fallen angel, also known as 'The Morning Star', but here he's also Satan, the Devil, and all those other guys too. None of these figures have any part to play in Join Me, so we don't need to examine these things too closely. However, for the sake of parody, Satan is in the Join Me Top Trumps pack.