Conmun Spider

The Conmun Spider is visually identical to the Merchant Spider, except for white horizontal stripes across its body, though these fade into a very dark grey as they grow older.

They emulate the Merchant Spider in every way they can, except when they offer an item to someone and receive an offering to hand it over, they sprint away with both.

If caught, it'll offer both items back in a grovelling manner, but if the victim’s guard is lowered, they’ll scarper once again. Thankfully, Conmun Spiders are incredibly rare, and are outnumbered by the Merchant Spider by at least fifty to one, though estimations are vague.