Large mammal also known as a killer whale (4)
I believe the answer is:
orca
(Other definitions for orca that I've seen before include "Large mammal" , "swimmer in black and white" , "grampus" , "Massive killer" , "Large predator" .)
I believe the answer is:
orca
(Other definitions for orca that I've seen before include "Large mammal" , "swimmer in black and white" , "grampus" , "Massive killer" , "Large predator" .)