I’ve seen two-headed snakes and turtles in zoos.
I’ve seen the stuffed two-headed calf in Wall Drugs, South Dakota.
But I’d bet some “primitive” animal is going to win that contest.
Drysophola(sp?) flies, or planaria worms?
Any guesses?
I don’t know of any two headed species, but man is the only two-faced animal.
Two Faced Animal? I think I dated a girl like that once…
A saw a two-headed snake in the wild, once. It was on a tiny little island in the middle of a nearby lake. I think that it was a common gardner snake, although my memory insists that it was several times larger 
That was a good 10 or 12 years ago, and I haven’t been back to that island since.
i would go with the planaria worms. you can’t beat something that looks like a little two-headed penis.
The U.S. Congress.
The most common examples I’ve seen are turtles and snakes.
Don’t you people read the tabloids!!!
It’s the “Two - headed Raymond Burr babies”.
Duh!
If you spend time in a salmonid hatchery (salmon, trout, char…), you’ll see a few dozen double-headed and siamese-twin fish every season. They never grow very big though, because it’s part of your job to remove and dispose of them. I don’t know how common two-headed fry are in the wild, and as adults they’re unheard of. Even with all the unusual fertilization and hatching practices, the rate is still low… maybe 2 dozen freaks in a million normal fish.