Sewer alligator

The sewer alligator is a giant alligator that has been reported to thrive in the New York City sewer systems. It is probably one of the most common urban legends. Although experts claimed alligators can't reproduce or live in the sewer system as it would be freezing in the winter and alligators always need warmth to survive and they could survive eating rats and trash if they never surfaced, but they would all be killed by the polluted sewer water, the legend is based on historical facts. In 1935, two young youths were shoveling snow down a Manhattan manhole and they spied an alligator in the sewers. When they got it out of the system, they killed it with their shovels. The beast measured 8 feet (2.4 m), and this began the rumor that families were flushing their pet gators down toilets when they became too big.

MonsterQuest expeditions have found alligator nests and human remains in the sewer system and they all spotted a newt or a salamander. A video taken in New Orleans shows an 8-foot alligator that escaped hurricane katrina by hiding in the sewers. The animal was found by several sewer workers several weeks later, in apparent good health. While it is unknown how this alligator got in the sewers, Dr. Kenneth Krysko, a herpetologist, is not at all surprised.

Description
Eyewitnesses describe alligator 14 feet long and weighing over a thousand lbs. This apex predator's powerful jaws can crush bones. This resilient monster is known to thrive in the world's most inhospitable areas. The New York City's sewage system, which processes 9,000,000 gal. of waste weekly, would fit that description.