I have voted frogs but agree with three-fingers and would defo add some fish to it mysel, creating a little environment that would be nice and easy to maintain.
How about 1 x Dwarf Puffer in a heavily plnted and decorated tank with a few snails to hopefully keep up the food supply for your little blighty!!
The cories would be great also and would certainly keep you entertained with maybe a small shoal of tiny tetra as well. There really are a lot of options, even in a teeny-tiny tank!!