The jago-nini (Punu or Sira: "giant diver") was a cryptid reported from Gabon by Trader Horn. It was described as an amphibious animal that preyed on West African manatees and humans.
"Aye, and behind the Cameroon there's things living we know nothing about. I could 'a' made books about many things. The Jago-Nini they say is still in the swamps and rivers. Giant diver it means. Comes out of the water and devours people. Old men'll tell you what their grandfathers saw but they still believe its there. Same as the Amali I've always taken it to be. I've seen the Amali's footprint. About the size of a good frying pan in circumference and three claws instead of five."