The Megalodon Shark is not just a character in creature features*. Megalodon Sharks lived between 15.9 and 2.6 million years ago. They could grow up to 59 feet. The Discovery Channel features Megalodon during Shark Week and has a cool interactive site in its Sharkopedia. For more details about Megalodon including eating habits, environment and what it liked to eat visit Megalodon in their Sharkopedia.
Megalodon burst onto the movie/tv screen in 2009 with Mega Shark Vs. the Giant Octopus. The most recent adventure is the 2015 outing Mega Shark Vs. Kolossus.
*See IMDB for more info on mega shark movies including Mega Shark vs. Kolosuss (2015).