Real world article
(written from a production point of view)
As implied in the first draft script of the Star Trek: Deep Space Nine fourth season episode "Body Parts", a Klingon wildebeest was a large animal kept by Klingons.
In the script, Keiko O'Brien commented that, during the first part of her pregnancy with Kirayoshi O'Brien, she sometimes felt like she couldn't eat anything but occasionally, at other times, felt she "could eat a Klingon wildebeest."