Gemsboks are a species of antelope who appear during the movie, Khumba.
The Gemsboks showed up at the enclosed gate of twigs the zebras built to secure themselves, to ask for some water for the elder female, The Gemsbok Elder. They asked the zebra Khumba who let them in even though a drought was going on. The Zebra Clan was shocked that khumba did that and exiled the Gemsbok. Outside the perimeter, the huge leopard, Phango, was attacking some Gemsboks.
Towards the end of the story, the Gemsbok Elder saved Khumba. They were there to see Khumba make it out alive.