I don't know how exactly I stumbled onto this, but there is a company that sells a mouse with an actual spider inside. It's clearly visible through the transparent chassis, and no, I'm not adding this one to my wish list.
I might call up Bugs-B-Gone, though, to see if John Goodman is available to reprise his role from Arachnophobia, should this thing ever show up on my doorstep. Or move, I'm not really sure.
Realbug, the company that makes this thing, figured a giant spider in the palm section of a mouse was not sufficient to give people nightmares, so it made the damn thing glow in the dark.
I get it, though—some people find this sort of thing cool, I'm just not one of them. In case you are wondering, Realbug makes other mice with various creatures inside, including scorpions, centipedes, beetles, and butterflies. And if you really want to lose points with someone who's squeamish with all sorts of insects, there's even a model with a spider and a scorpion, that would make for a terrible anniversary gift.
At least they're cheap (the spider mouse sells for $22.52 on Amazon). Pricing likely indicates an underwhelming spec sheet (not disclosed), but if you're not into spiders, the dpi hardly matters.