Grumpy Cat became an instant Internet sensation after images of her curmudgeonly facial expression were posted to Reddit back in 2012. But now there's a new grouchy animal in the mix, and it might take the crown as the grumpiest animal of them all. Meet Grumpy Frog, the crankiest frog in the world.

This incredibly unusual-looking amphibian (Breviceps fuscus), endemic to South Africa, is commonly called the black rain frog — an apropos designation seeing as it looks like it lives with a black rain cloud following it everywhere. It is, of course, not actually a grumpy animal — it just looks like one — but it's difficult not to be anthropomorphic about a mug like this frog's (Anyone else think they look like frowning purple emoticons?)

The black rain frog can be found in the temperate forests and Mediterranean-type shrubby vegetation of the southern slopes of the Cape Fold Mountains, South Africa. It lives in areas ranging from sea level up to over 3,000 feet, and is a burrowing frog, making its home by digging in the forest soil. Unlike many frogs, it breeds by direct development, not associated with water. 

Among the frog's very un-grumpy (and actually really considerate) attributes are that males make excellent fathers, sticking around to guard the eggs until they hatch. Females also secrete a sticky substance on their backs so that the plumpy males don't roll off while mating. 

If Grumpy Frog has any real reason to be grumpy, it's because the species dislikes human development. Though its natural habitat is largely undeveloped, the frog is not well-adapted to afforestation, the spread of alien vegetation and frequent fires.

When they feel threatened, black rain frogs can puff themselves up like a balloon — kind of like a pufferfish. When they puff up while burrowing, they can become incredibly difficult to dislodge from their holes.

When it transforms into a cranky balloon, best to leave Grumpy Frog alone!

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