http://www.snopes.com/photos/animals/wcgator.asp
The photograph displayed above is genuine and corresponds to the following account of an alligator killed by game wardens near West Columbia, Texas (a town whose claim to fame is its status as the First Capital of the fledgling Republic of Texas), in April 2005:
Game wardens forced to shoot alligator
Published April 16, 2005
WEST COLUMBIA - Anita and Charlie Rogers could hear the bellowing in the night.
Her neighbors in Bar X Ranch had been telling them they had seen a giant alligator in the bayou that runs behind their house, but they dismissed the stories as exaggerations.
"I didn't believe it," Charles Rogers said. Friday they realized the stories were, if anything, understated. Texas Parks and Wildlife game wardens had to shoot the beast.