Theloderma corticale carries a dense covering of tubercles, warts and low ridges over a mottled green, black and rust-coloured skin. Pressed against wet rock or a mossy log in a limestone cave, the outline dissolves. The camouflage works on texture as much as colour, breaking up the smooth silhouette that would otherwise identify a frog.
If discovered, the frog adds a second behaviour. It draws its limbs in tight, curls into a rounded ball and remains completely still, a form of thanatosis or death feigning. To a visually hunting predator the result resembles an inedible lump of vegetation rather than prey worth pursuing.
The species is semi-aquatic and often occupies flooded cavities in karst. Females attach eggs to surfaces just above standing water inside caves and tree holes, and the hatched tadpoles drop into the pool below. The frog is common in the international pet trade, and captive-bred stock is now widely available, which reduces though does not remove pressure from wild collection.