Any of various extinct animals thought to form an intermediate between terrestrial mammals and modern whales, with the ability to walk; (now) especially Ambulocetus natans, an amphibious quadruped of the Eocene epoch, known from fossil remains discovered in Pakistan.
Origin
1980s.
Definition of walking whale in US English:
walking whale
noun
Any of various extinct animals thought to form an intermediate between terrestrial mammals and modern whales, with the ability to walk; (now) especially Ambulocetus natans, an amphibious quadruped of the Eocene epoch, known from fossil remains discovered in Pakistan.