FRONTIERS OF ZOOLOGY Dale A. Drinnon has been a researcher in the field of Cryptozoology for the past 30+ years and has corresponded with Bernard Heuvelmans and Ivan T. Sanderson. He has a degree in Anthropology from Indiana University and is a freelance artist and writer. Motto: "I would rather be right and entirely alone than wrong in the company with all the rest of the world"--Ambroise Pare', "the father of modern surgery", in his refutation of fake unicorn horns.
It seems that when bestiaries in Western Europe wanted to illustrate a crocodile of the Nile, thy fell back on illustrations of a different kind of animal understood as a "Crocodile" in its place. This was definitely a hairy mammal with what looked like a row of spines on its back and a head like a hound's. This was the version current in Britain, Germany, France and adjoining areas. Peter Costello's book In Search of Lake Monsters in his chapter concentrating on Ireland, mentions a creature with a fearsome reputation known as the "Irish Crocodile" which is probably the Master-Otter. One of the early sightings off of Norway and mentioned to Pontopiddian concerns a four-legged creature caught in a net by some fishermen and which he said 'must resemble a crocodile' and which is also very likely the same creature. Back in the Mediterranean, the confusion was somewhat alleviated because artists were more familiar with actual crocodiles instead.
The bestiary illustrations usually are about a fable where the crocodile swallows a winged dragon but the dragon chews its way through though the crocodile's abdominal wall. This story is actually a hero story originally told with a human protagonist (Who dug his way out with the help of his knife) and it may actually have been native to Africa originally. It is also interesting that the "Dragon" as illustrated in the bestiaries appears to be one of those winged serpents or wyvern types. That would also be an interpretation made in Western Europe especially. Both of these animals are represented in what passed for a realistic portrayal back then. The Master-Otter or Dobhar-Chu was sometimes also said to attack humans, and this is illustrated in the last picture at the bottom.