From above, there isn’t anything particularly strange about glass frogs. In fact, they look about as normal as a frog can possibly get. However, a glance at their bellies provides a much more unusual view.
Only the skin on a glass frog’s back contains any colour, and even then it doesn’t have much. Across the rest of their body, they’re completely see-through. This means that when you look at one of these amphibians from underneath, you can see straight through their bodies, past their organs, and out the other side.
Their transparent skin creates a rare form of camouflage. To any predators, the frog is the exact same shade of green as whatever it’s sitting on. Their incredibly clear legs help to blur the outline of their mostly-clear body, making them even harder to spot. No matter which leaf the glass frog chooses to hide on, it will always be perfectly disguised.
Lachlan Writes Science 