A brewery in Denver has a new beer that people will go nuts for. It's called Rocky Mountain Oyster Stout and it's made with real bull testicles.

The Wynkoop Brewing Company will tap its the first keg of the new beer on Monday. The idea for the beer actually started as an April Fool's joke. But when many people thought it was serious and started asking for samples of it, they decided to make it for real.

The brewery will teste it out on beer drinkers next week at the Great American Beer Festival in Denver.