David Howells Fleay was an Australian scientist and biologist who pioneered the captive breeding of endangered species, and was the first person to breed the platypus in captivity.

The platypus, sometimes referred to as the duck-billed platypus, is a semiaquatic, egg-laying mammal endemic to eastern Australia, including Tasmania. The platypus is the sole living representative or monotypic taxon of its family Ornithorhynchidae and genus Ornithorhynchus, though a number of related species appear in the fossil record.