Ocean predator that sleeps with one eye open (4)

I believe the answer is:

orca

(Other definitions for orca that I've seen before include "Large predator" , "swimmer in black and white" , "27 [WHALE]" , "Killer-whale" , "Marine creature" .)

I've seen this clue in the LA Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.