My mystery animal is?

                  Colorful as a quilt spike as needles as slimy as a slug big and small like a toy car .It lives in rivers in Africa it eats bugs and small animals .It can not fly and it can only swim and jump out of the water .It has rely sharp teeth and big red lips .It creeps up behind its pray and snap! It bites it's head off and eats it.It hates shallow water because Dear,and Alligators and a lot of other animals can pick then up out of the water hull.
                                                                     My animal is?