Slug Hitchhikers

[Cap'n]

I have a couple slugs that I can't find an ID for. They both are shaped like clasic slugs (land or sea) with a slightly larger area in their midsection. There are no frilly appendages just a couple antenae at the front. They both have a single white dot near the middle but not centered. One is tones of light grey, the other is pitch black.

Any ideas?