Just what it sounds like....

From the Scottsdale Tribune:

"Rocky Mountain oyster high on the menu
By Marija Potkonjak, Tribune
Sliced into small pieces, deep fried and served with a side of ranch dressing or Tabasco sauce, they could be mistaken for a smaller version of calamari. But if you think Rocky Mountain oysters are seafood, you definitely shouldn’t be eating them.

Whatever you call them — barnyard jewels, Montana tendergroin, cowboy caviar, calf fries — bull testicles are a delicacy in some parts of the world and will be the plat du jour at the inaugural Testicle Festival today and Saturday at Mazatzal Casino south of Payson.

But if you can’t make it out of town this weekend, you can get breaded, deep fried Rocky Mountain Oysters at Rawhide Wild West Town in Scottsdale.

"With enough beer people will eat anything," said John Stanley, Rawhide’s food and beverage director. "When you see them cooked, they don’t look that bad, but when you see them raw they’re kind of scary."

Rocky Mountain oysters have been on the menu at Rawhide "forever," Stanley said. But it isn’t the only way to prepare them—you can also saute, poach or braise them.

Dining on animal testicles dates to Roman times when a common medical treatment for an ailing organ was to eat the corresponding organ of another animal. Voila — ancient Viagra.

Modernity didn’t kill the practice. It just spread to other parts of the world. Asians gobble them up as an aphrodisiac.

Europeans dine on them, but the fascination is strictly epicurean.

Nibbling on Rocky Mountain oysters in the United States is cowboy tradition. Back in the days when men drove cattle, cowboys would castrate male calves en route to make them fatter and easier to handle. Since it’s anathema to the cowboy to let anything go to waste, the testicles were sliced into edible portions, thrown onto a skillet and cooked until they popped out of the "shell."

In the modern West, the shells are removed before the testicles are thrown into a skillet, Stanley said. Festivals celebrating the dish are held throughout the West. Rocky Mountain oysters are especially popular in Colorado, where they’re on the menu at Mile High Stadium, and in Montana, home to the Testicle Festival at Rock Creek Lodge, the raunchiest of them all — it’s sponsored by Hustler magazine.

But at Mazatzal Casino, the atmosphere will be tame. You can sample this delicacy or if you’re really brave, wolf them down during the eating contest at midnight.

So what do Rocky Mountain oysters taste like?

Whatever you dip them in."