Wildlife endangered species. Awesome colorful frogs collection. The glass frogs are frogs of the amphibian family Centrolenidae. Tthe abdominal skin of some members of this family is transparent. The internal viscera, including the heart, liver, and gastrointestinal tract, are visible through the skin, hence the common name is given as glass frog. Glass frogs are arboreal, meaning they mainly live in trees, and only come out for mating season.