There is a video game called Goat Simulator. Inside of the game one can find a Diablo 2 style Secret Cow Level complete with noisy, bipedal, angry attack cows.
This seems perfectly logical to me, but try using that opening sentence on an older relative at an upcoming family event, and count on them looking baffled and/or patting you on the head and saying, “that’s nice, Dear.”
Diablo 2 Secret Cow Level inside Goat Simulator:
Thanks to Timmeh for the news tip.