Here's a simple and inexpensive DIY idea to spook up any entry!
I made these using old dress socks, stuffed 'em with soft pillow stuffing, tied 'em up and added some webs on the the outer layer. Before I added the white webs and spiders, I spray painted over them with green and orange fluorescent paint so that they would pop under the black light. I also popped on some extra eyeballs I had laying around.
COST: Virtually nothing! (used materials I already had.)