Almost 400 million years ago, our ancestors slowly emerged from the sea to breathe air and populate the land.

It may surprise you to know there’s another species making that same transition right now.

It’s the mudskipper, a 4- to 12-inch fish that looks like a frog with only front legs. It has a large frog-like head and smooth, green and brown skin dappled with spots.

The mudskipper lives in tropical and subtropical coastal flats and spends its time under or out of water, depending on the tide.

During high tide, it lives in a burrow in the muddy floor, safe from larger fish and other predators.

During low tide, it emerges to pull and wriggle its way across the mud, where it flops and leaps in mating dances.

It can breathe water with its gills. Or breathe air by absorbing oxygen directly through the skin of its throat.

But perhaps what’s most notable about the mudskipper are its eyes. Like land animals, they’ve lost the ability to focus underwater, and require some protection to keep them moist.

But the mudskipper has not yet developed eyelids, so it must repeatedly extend and retract its eyes into its head, a primitive form of blinking.

Studying mudskippers allows scientists to imagine how the vision of our earliest mammal ancestors may have developed—a legacy of sight that’s been passed down to us today.

Here’s looking at you, skipper.