Uhn... a hissing cocaroach, some type of tarantula? I had read up on those two briefly when researching for my 5 gallon, I imagine they could handle a 1 gallon dip.
I have a 2 gallon 'shrimp bowl' on my desk, right now. It's heavily planted, and has two ghost shrimp in it. I think it's neato. Shrimps are interesting creatures.