What Plant is this?

[BonnieLorraine]

I would avoid using Euphorbias, their sap can be rather damaging (I think I have another post on here on the dangers of pencil trees). Croton sap can be irritating as well, I would probably only use them with smaller frogs I was sure wouldn't be breaking leaves. The plant in the pictures is most definitely Peperomia prostrata grown so that it is hanging down, most likely as an epiphyte, though you usually see it as a ground cover.

[Bombina Bob]

Yes, Grimm on the Dendroboards can have a huge variety of plants in his tanks! he may have a list of them on any of his threads relating to plants.