If I saw some of these I would be scared
In 2014 a giant salamander emerged from the Kamo River in Japan. Landed appearances of the giant creature are considerably rare due to them making their home underwater and being only active at night. Japanese giant salamanders are the second-largest salamanders on Earth, surpassed only by the closely related Chinese giant salamander. They feed on insects, frogs, crabs, shrimp, and fish; but since the 1950s, their population has declined rapidly due to habitat destruction and overhunting.
parasitic louse (crustacean family) that attacks fish. Enters fish through gills, then attaches itself to base of tongue. Louse restricts blood flow to tongue, feeding off it, causing the tongue to wither and die where it then takes its place. Then it lives in the fishes mouth, working as a fully functioning tongue and living off its blood and saliva. Apparently this does not harm the fish and is the only known case of a parasite replacing a whole organ.
Whorl Shark (Helicoprion) lived 280-225 million years ago. Modern sharks continue to grow teeth throughout their lives and shed old teeth. Ancient sharks grew new teeth, but kept the old teeth as well. In some species, old teeth migrated to the face to make room for teeth in the jaw. In the whorl shark, old teeth were just rotated around.