Cockatrice ; /ˈkɒkətrʌɪs,ˈkɒkətrɪs/ ; noun: cockatrice ; plural noun: cockatrices ; a mythical beast that is hatched by a serpent from a cock's egg and that has a deadly glance ; in heraldry : a mythical animal depicted as a two-legged dragon (or wyvern) with a cock's head. ; origin : late Middle English: from Old French cocatris, from Latin calcatrix ‘tracker’ (from calcare ‘to tread or track’), translating Greek ikhneumōn.