Mascot
The Darwin developers decided to adopt a mascot in 2000, and chose Hexley the Platypus, over other contenders, such as an Aqua Darwin fish, Clarus the Dogcow, and an orca. Hexley is a cartoon platypus who usually wears a cap resembling a demon's horns. He carries a trident, similar to the BSD Daemon, to symbolize the daemon's forking of processes. Hexley was designed by Jon Hooper. Apple does not sanction Hexley as a logo for Darwin.
Hexley's name was a mistake: it was originally supposed to be named after Thomas Henry Huxley, a 19th century English biologist who was a well-known champion of Charles Darwin's theory of evolution (nicknamed "Darwin's bulldog"). However, ignorance led not only to a mistake in Huxley's name, but who he was thought to be. The developers apparently thought he was simply Darwin's assistant, when in fact he was a prominent biologist in his own right. By the time the mistake had been discovered, it was deemed too late to change, and the incorrect name "Hexley" was kept.
Read more about this topic: Darwin (operating System)