22. The Carrows
Onto the villains who barely had any presence at all; starting with the Carrows.
They're mentioned fairly often before their defeat, but they amount to very little. They get some interesting set up involving them torturing Hogwarts' students, but they mostly do nothing. When the confrontation with Snape comes to a head, they stand in the background, get knocked out with a single spell, and are never seen again.
It's a shame, because Amycus is played by the brilliant Ralph Ineson. They should've been treated better, but instead they get pushed aside like they're nothing.