I followed a tutorial from gardener's supply where the terrarium came from, though I used materials we already had on hand (except for moss, I bought that from our local nursery). Inside are six different tiny ferns - different leaf patterns and shades of green. It's really beautiful.
It's really hard to photograph because the glass is so reflective, but inside is this beautiful tiny jungle of green. Oliver kept insisting we put tiny jungle animal figurines (leftover from his Valentines) inside the "jungle." The only downside was that he then wanted to play with the terrarium, so the animals were relocated to an artificial plant.