Answer:

gnu

Answer	Crossword Clue
GNU	Black wildebeest
GNU	Wildebeest
GNU	African runner

GNU	Crossword antelope
GNU	Ox-headed antelope
GNU	Was acquainted with an antelope?
GNU	Bearded antelope
GNU	Hartebeest kin
GNU	Operating system that's "not Unix"
GNU	Bearded grazer
GNU	Zoo favorite

GNU	Wildebeest's alias
GNU	Novel-sounding grazer
GNU	Serengeti grazer
GNU	Prey for a pride
GNU	Serengeti critter
GNU	Hyena pack's prey
GNU	Bearded beast
GNU	New homonym?

GNU	Oxlike beast
GNU	Migratory African grazer
GNU	Animal on some South African coins
GNU	Bearded bovid
GNU	African antelope
GNU	Safari sight
GNU	Oxlike antelope
GNU	Bearded grassland dweller

GNU	Horned grazer
GNU	Animal with a silent first letter
GNU	Savanna lion's prey
GNU	Serengeti stampeder
GNU	African grass eater
GNU	Antelope seen on safaris
GNU	Lion's prey
GNU	Serengeti denizen

GNU	Migratory African critter
GNU	Safari sighting
GNU	Savanna sighting
GNU	Serengeti antelope
GNU	Animal like new?