It was a dumb pun that originated in a What in the world will GW do to Chaos Dwarfs in AoS train of conversation. An offhand musing that gained traction, especially since the damnable high elves took our cows. (Edit: spelling should be high aiolielves…)
THEY TERK 'ERR COWS
Community has since run with the joke in a serious manner and as usual it has turned into something far greater than GW could hope to achieve. The Hoary Sea Father cometh