High Quality Content by WIKIPEDIA articles! The Thick-billed Raven (Corvus crassirostris), a Corvid from the Horn of Africa, shares with the Common Raven the distinction of being the largest in the Corvid family, and indeed the largest of the bird order Passeriformes (perching birds). They measure 60-64 cm (24-25 in) in length and weigh 1.5 kg (3.3 lbs). It has a very large bill that is laterally compressed and is deeply curved in profile giving the bird a very distinctive appearance. This bill is black with a white tip and has deep nasal grooves with only light nasal bristle covers.