mud|skip|per

mud|skip|per «MUHD _SKIHP uhr», noun.

a small fish, a variety of goby, with movable pectoral fins and a muscular tail, found in shallow coastal waters from western Africa to Polynesia; tree climber. It often moves about on mud flats, jumping and climbing roots after insects. »

Of all living fish, the mudskippers…demonstrate most clearly how terrestrial vertebrates with four legs could have evolved from primitive swimmers with no legs at all (New Scientist).