The story of a large reptile roaming Ledyard, Conn., was no urban legend. Police say an officer shot a monitor lizard to death Sunday after a resident called 911 to report what she believed to be an alligator attacking the chickens in her coop. The officer shot the reptile to protect patrolmen, the town’s animal control officer, and the chickens, Lieutenant Michael T. Finkelstein said. Monitor lizards can be as big as some alligators, reaching lengths of 6 to 7 feet. They are not native to Connecticut and are illegal in the state. Police suspect the one killed Sunday had been an illegal pet that escaped or was abandoned.