What is "catoblephas gnu"

Gnu \Gnu\, n. [Hottentot gnu, or nju: cf. F. gnou.] (Zo["o]l.) One of two species of large South African antelopes of the genus Catoblephas, having a mane and bushy tail, and curved horns in both sexes. [Written also gnoo.]

Note: The common gnu or wildebeest ( Catoblephas gnu) is plain brown; the brindled gnu or blue wildebeest ( C. gorgon) is larger, with transverse stripes of black on the neck and shoulders.