Today marks the third birthday of Blizzard Entertainment’s Diablo III, and to celebrate, the developer has unleashed the Cowpocalypse on its players.

Starting today and ending on May 21, those playing on the PC, PlayStation 4, and Xbox One versions of Diablo III will most likely run into special Treasure Goblins that have Cow Level portals pop up once they’re defeated.

We would caution players from actually entering these portals as they contain an unhealthy amount of extremely agitated bovine wielding large weapons. The amount of cow-related puns are dangerously high, which you can see for yourself in the trailer for the event below.

This special event is not available on the PlayStation 3 and Xbox 360 versions of Diablo III, but they’ll still be able to celebrate by receiving a 100% EXP and Gold buff.

Now go make us some burgers out of the millions of cows you’ll be slaughtering this week.