Here's your unicorn plant. It's a Gesneriad, grows slow, spreads via underground rhizomes (also very slowly) and has thick, textured and leathery leaves.

You'll receive a plant similar to, or larger/more mature than the plant in photos 1-4.

The large plant in later photos is my mother plant.

High humidity terrarium culture, handles wet soils, fertilizing with terrarium safe fertilizer, and NOT drying out or quick humidity drops. These are all experimental conditions. Info is sparse. I have had good luck with Cocochip (washed thoroughly!) perlite and akadama blended media.