As long as a plant is slow-growing, small and suited to the terrarium you place it in, it is suitable for a terrarium.
Plants that are suited to tropical jungle climates love the humid and balmy conditions inside of a closed terrarium. Desert-type plants, on the other hand, thrive in the dry conditions that an open terrarium brings. As long as a plant is slow-growing, small and suited to the terrarium you place it in, it is suitable for a terrarium. In the end, the best plant for your terrarium is up to you!