This frowning frog isn’t actually disappointed or sad — that’s just how the Black Rain Frogs look. When the Black Rain Frogs feel disturbed and threatened, they will puff up and enlarge their body, adopting a more aggressive behavior. They have a round body with short limbs and toes. The species is only found on the southern slopes of the Cape Fold Belt in South Africa at elevations of up to over 3,300ft (1,000m). Colouration is typically dark brown or nearly black, with a slightly lighter ventrum and no pigmented patterns.
But that doesn’t mean that the Black Rain Frogs hate company. On the contrary. Come mating season, the female will secrete a sticky substance on its back to keep the male from falling off; this is known as adhesive amplexus. It literally refuses to let go of its partner.
Males call from within burrows (sometimes while guarding eggs) and from above-ground vegetation. The call is a short (0.2 s) “chirp”, with a dominant frequency of 1.8 kHz. The eggs are laid within burrows with small (15 mm) openings and about 30–40 mm deep. Each nest consists of approximately 42–43 yellow eggs that are 5 mm in diameter inside 8 mm capsules.
Here are some interesting images of this mysterious creature: