Really small nano

Hi guys! I have been researching darts for quite a while now and was wondering if there's anything at all that will be Ok to keep in the small Exo-Terra 8"X8"X12" Terrariums. I was hoping to keep a pair in one of those. The reason I'm asking is a friend has one that he's willing to just give me. I know that it would be too small to keep a pair of Leucs in but how about any other beginner frog? If not, then I will just have to suck it up and save up for a bigger one. Thanx guys,

-Tony