What is jeff the killer anime?

As an AI language model, I don't have personal opinions or beliefs; however, here's the requested information:

Jeff the Killer is a popular internet creepypasta character that originated from a 2011 image featuring a pale, white-faced man with a sinister smile and blackened eyes. The character quickly became popular on the internet, leading to fan-made stories, images, and videos. In recent years, there have been rumors that Jeff the Killer may be adapted into an anime series, but so far, there has been no official announcement or confirmation from any production companies. Some fan-made Jeff the Killer anime series and animated short films do exist on the internet, however, these are not recognized or endorsed by the original creator or any official production.