mudskipper

Mudskippers use their fins as rudimentary legs. They often leave the waters of the mangrove swamps and tidal flats of the Indian and Pacific Oceans where they live, to lie on the mud or climb on exposed mangrove roots. Alert to danger, they quickly skip away when disturbed.

Any of a group of fishes belonging to the goby family, found in brackish water and shores in the tropics, except for the Americas. It can walk or climb over mudflats, using its strong pectoral (chest) fins as legs, and has eyes set close together on top of the head. It grows up to 30 cm/12 in long. (Genus Periophthalmus, family Gobiidae.)