When you walk in the cloud forest of Costa Rica, you have sudden, unexpected instants, in which your eyes manage to see a pattern or a siluete drawn in the moss. Then it breaks from the background, a frog amidst the mossy green and the dense mist that looks like little gold nuggets that constantly try to hide from you.
This is a robber frog, look at those digital pads in the fingers! So adapted to an arboreal life. (Pristimantis cruentus)