Now my idea’s are to make these things quickly without much trouble so above can be done a few ways.
You can get either premade cupcakes and put them on the plate or a chocolate coated biscuit like say a mint slice.
Use chocolate covered pocky as the legs or chocolate sryup to do the design on the plate and you have spiders :)
Also if you have some white chocolate you can quickly melt then get some chocolate biscuits and do a design ontop of it like a skull, spider web etc.