One of the most striking mystery birds of paradise is the enigmatic Elliot’s sicklebill. Little context is known about this cryptid, but two adult specimens were collected presumably by someone named Elliot in 1872. They were collected somewhere in the Bird’s Head Peninsula in the westernmost reaches of New Guinea, which are now kept separately in the British Natural History Museum and the Dresden Natural History Museum.
Elliot’s sicklebill has a very unique appearance, with very long iridescent tail feathers, green plumage, black and blue wings, and a yellow band on their neck. Similar to other unknown birds of paradise, Elliot’s sicklebill is dismissed as a hybrid, usually of a black sicklebill and an Arfak astrapia. Some cryptozoologists and ornithologists have pointed out that it makes little sense as to why two very genetically and morphologically different species would or could interbreed. Also of note is that neither parent species are as large as Elliot’s sicklebill, and also lack the lobed mouth, green breast and yellow band on its neck.