Dude, it's nearing Halloween.
Monsters. Frankenstein, the Mummy, Wolfman, the Swamp Thing and more.
You don't even have to draw them out like my Dad did for my targets when I was growing up. Just hit the nearest doller store the day after Halloween and you should be able to stock up cheap, easy and fun targets.
They may have issues shooting at "humans", but most people can handle shooting ghosts, zombies and monsters.
Plus, I think it has a nice subtle underlying message.
