This crystal and black Swarovski tarantula necklace is quite a statement piece. I don't know if I'd personally have enough vavoom in my personality to carry this off. It might look stunning with a low-cut long black velvet gown.
The tarantula necklace comes in many colors, most of them not goth-friendly. I like this purple one though.
It's also nice in a vivid blood red.
I don't really care for the matching earrings, but here's a nice tarantula choker-style necklace featuring just one large spider.