Dieudonné's+Dragon

Read about Dieudonné de Gozon and the dragon here. This is the only documented case of a knight defeating a "dragon". One theory is that a baby Nile Crocodile, bought in the exotic markets of Turkey, was brought to Rhodes as a pet and thrown away when it got too big and aggressive. Rhodes' swamplands were a perfect place for the creature to thrive. An adult Nile Crocodile is the second-largest reptile in the world (see photos and facts below). Both the islanders of Rhodes and the European Knights Hospitaller would never have seen a crocodile before, but - thanks to the accidental finding of dinosaur fossils like T-Rex and Pteranodon over the ages - they //did// have a word for 'giant reptile': dragon.

What is known is that the skull of the beast that Dieudonné killed remained hanging over the main gate of the Fortress of Rhodes until the 19th century, when a visiting biologist identified it as that of a giant reptile. Namely: crocodile. From Wikipedia:

Characteristics
Nile crocodiles have a dark bronze colouration above, with black spots on the back and a dirty purple on the belly. The flanks, which are yellowish-green in colour, have dark patches arranged in oblique stripes. There is some variation relative to environment; specimens from swift-flowing waters tend to be lighter in colour than those dwelling in lakes or swamps. They have green eyes. Like all crocodiles, the Nile crocodile is a quadruped with four short, splayed legs, a long, powerful tail, a scaly hide with rows of ossified [|scutes] running down its back and tail, and powerful jaws. The nostrils, eyes, and ears are situated on the top of the head, so the rest of the body can remain concealed underwater. The coloration also helps to camouflage it; juveniles are grey, multicoloured, or brown, with dark cross-bands on the tail and body. As it matures, it becomes darker and the cross-bands fade, especially those on the body.

Size
The Nile crocodile is the largest crocodilian in Africa and is the second-largest crocodilian after the saltwater crocodile. The male crocodile usually measure from 3.5 to 5 m (11 ft 6 in to 16 ft 5 in) long, but very old, mature ones can grow to 5.5 m (18 ft 1 in) or more. Typical Nile crocodile weight is from 225 to 550 kg, though exceptionally large males can range up to 900 kg or more, in weight. The largest accurately measured male, shot near Mwanza, Tanzania, measured 6.47 m (21 ft 3 in) and weighed about 1,090 kg. The largest living specimen is purported to be a man-eater from Burundi named [|Gustave]; he is believed to be more than 6.1 m (20 ft 0 in) long. Such giants are rare today; before the heavy hunting of the 1940s and 1950s, a larger population base and more extensive wetland habitats meant more giants. Average Nile crocodile size (green) along with size of [|Gustave] (grey) compared to a human.