The indian ocean walkman (Inimicus didactylus) is closely related to the stonefish, it has a "knobbly" surface and has venomous spines to ward off predators. a nocturnal fish they are usually  fairly sedentary during the day, mostly buried into the seabed. At night the fish is an ambush predator  but has no known natural predators. When disturbed it may fan out it's pectoral and caudal fins  as a warning but it is generally reluctant to move once it is dug into the sand. When it does move it crawls slowly using four lower "claws" two on each side of its pectoral fins as "legs"

Filmed by Mima she says

"This is my 1st Indian Ocean Walkman in Koh Tao, It was quite exciting to see it and show it to the students I was filming.I spent a lot of time around it and I started actually talking to it at one point":)