- walrus, seahorse, sea horse - either of two large northern marine mammals having ivory tusks and tough hide over thick blubber
--1 is a kind of pinniped mammal, pinniped, pinnatiped
--1 is a member of Odobenus, genus Odobenus
--1 has particulars:Atlantic walrus, Odobenus rosmarus; Pacific walrus, Odobenus divergens - seahorse, sea horse - small fish with horselike heads bent sharply downward and curled tails; swim in upright position
--2 is a kind of pipefish, needlefish
--2 is a member of Hippocampus, genus Hippocampus