The Collaborative International Dictionary of English v.0.48:

Koodoo \Koo"doo\, n. (Zool.)
   A large South African antelope (Strepsiceros kudu). The
   males have graceful spiral horns, sometimes four feet long.
   The general color is reddish or grayish brown, with eight or
   nine white bands on each side, and a pale dorsal stripe. The
   old males become dark bluish gray, due to the skin showing
   through the hair. The females are hornless. Called also
   nellut. [Written also kudu.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Kudu \Ku"du\ (k[=oo]"d[=oo]), n. (Zool.)
   See Koodoo.
   [1913 Webster]

WordNet (r) 3.0 (2006):

kudu
    n 1: either of two spiral-horned antelopes of the African bush
         [syn: kudu, koodoo, koudou]