I found a very small, sea slug-looking critter hanging out in my overflow as I was doing a water change today. Tonight he produced a small cluster of tiny white dots - eggs? It's a short cylindrical cluster rather than the characteristic spiral grouping... His dorsal surface is very dark green with white spots, the ventral surface is white, and the rhinophores are dark green/black striped. His body is pretty plain, he's shaped pretty much like a typical land garden slug. He is about a centimeter long.

If anyone has any idea what he is, I'd really appreciate the info.

I'd post a photo, but I haven't made 5 posts yet ;)

The Sea Slug Forum - Home Page
Check here to see if you can find it. There are also some other identification sites that may help such as
Genus of Nudibranch & Sea Slug » Nudi Pixel
I hope this helps. Without good pics it is hard to even guess .

Post some more and upload a picture, it's really hard to identify some creatures with a picture let alone without one and besides we LOVE pictures!

+1 to what marlenez posted. Good useful links posted by tamableanimasl. Save them o your favorites for future ref. It might come in handy again for you or someone else you know and want to help.