Grox

They look exactly as they sound like.

'Grox' are the primary livestock of the Imperium of Man and look pretty much like Grimdark Lizard Cows (there, a free awesome band name for you). They're raised across countless number of worlds, because they can survive almost any environment, live on almost any plant food (including driftwood), breed prolifically and (as a welcome deviation from the usual grimderp) are actually pretty damn tasty. They're big (about 5 meters in length), agile and muscular. The only problem is that they're highly territorial, aggressive and generally need to be lobotomized to be wrangled and bred.