Inspired by the Damn Interesting website, here's a puzzle for you. How many of these creatures are imaginary?
The Amazonian Giant Centipede, Scolopendra gigantea, grows to about 35cm long, climbs onto the ceiling of big caves, hangs on by some of its back legs and catches bats to eat.
The crustacean Cymothoa exigua is a shrimp-like parasite that attaches itself to the tongue of a fish called the Spotted Rosesnapper. Once in place it drinks blood from the artery that supplied the tongue with blood. The tongue gradually withers away and the parasite takes over as its tongue for the rest of its life, supplementing its diet with food particles. It is the only known parasite to replace on of it's hosts body organs, and one has been found recently in UK waters.
The Tiger Quoll , Dasyurus maculatus, is mainland Australia's largest marsupial carnivore. When it's babies are born they are the size of grains of rice. Adults are about 4-7 kg in weight. Little is known about their biology and ecology, and they are an endangered species.
The Caddy, Cadborosaurus willsi, is a sepent-like sea creature living off the Pacific coast of North America. 5-15 metres long, sighted nore than 300 times in the last two centuries.
The Mongolian Tuba, Tööm ah. was described (in Welsh) by the explorer Realth Chalmers as "A small kid, which as far as I can tell is devoid of any limbs, save two large horns which in some stories are much sought-after by hunters.". Buzkashi is a game played across Mongolia and Central Asia, in which two opposing teams on horseback compete to move a legless goat over their rival's goal line. It is claimed that the game was originally played with tuba corpses, when tubae numbers were much higher before they were nearly wiped out by hunters. The Maastricht Hours, a fourteenth century prayer book originating from the Netherlands and now kept in the British Library, features, amongst other illustrations, a depiction of a goat with the head of a snail. This could be an indication that stories of the tuba had spread far beyond their point of origin in the mountains of East Asia, most likely during the rapid expansion of the Mongol Empire during the 13th century.
Answers here, here, here , here and here.