The Kasai rex is a gigantic theropod cryptid from the Democratic Republic of the Congo. It is said to be a surviving theropod dinosaur, such as Tyrannosaurus rex, though it has also been depicted as a huge monitor lizard.
Kasai Valley report
In 1932, Swedish plantation owner John Johnson (sometimes spelled Johanson) was traveling with a servant in the Kasai Valley. They encountered a rhinoceros and tried to avoid detection when a large creature rushed from the undergrowth and attacked the rhino. Johnson fainted and the servant ran away. When Johnson recovered, he saw the creature eating the rhino.
"It was reddish in color, with blackish-colored stripes," he said later. "It had a long snout and numerous teeth." He decided that the creature, 13 m (43 ft) long, was a Tyrannosaurus and also said "The legs were thick; it reminded me of a lion, built for speed".