You're looking at a "supergiant," a type of amphipod found at the Kermadec Trench off New Zealand, at an ocean depth of over 4 miles. Deep sea amphipods are not unusual, but they're usually only about 3/4" to 1" long. As you can see in the photo above, the supergiants are a lot bigger:
Alan Jamieson, from the University of Aberdeen's Oceanlab, said: "It's a bit like finding a foot-long cockroach."
"I stopped and thought: 'What on Earth was that?' This amphipod was far bigger than I ever thought possible."
The strange animals were found using a large metal trap, which had been equipped with a camera, housed in sapphire glass to keep it safe from the high pressures of the deep sea.