I think a species only of African Dwarf Frogs would work in the 10 gallon. They prefer tanks that aren't too high! Not sure how many you could keep in there, my guess is maybe 3 or 4? Many people have problems feeding them, and keeping them alive, but you can teach them a specific area of the tank where the food will be dropped. Also, they need very good water quality, so you need to be consistent with your weekly water changes.