This cute little Peperomia is found in Peru and Ecuador, and perhaps elsewhere in South America. Its leaves only grow to be about 1″, and the entire plant stays under 6″ in my experience. Perhaps given something to lean on, it could get a little taller. It is tolerant of a wide variety of terrarium conditions but doesn’t seem to like standing water on its leaves.
*update* after growing this plant for over a year and struggling to have robust specimens, I switched over to a well-drained potting mix and its color and growth have improved dramatically. It has gone from a slow-growing slightly finicky species to a fast-growing robust one.