Hushed Current

One day, Jesse, a young fisherman, woke up next to a wetland with no clue of how he ended up there. The only thing he remembered was coming to a party, then passing out in the comfort of his kitchen. While cleaning the mess he made, he noticed that one of his cassettes was missing so he ran straight back to the water where he thinks it might be. Left with no other places to search, Jesse dipped his hand into the wetland when suddenly his hand got pulled by a mysterious creature appearing right in front of his eyes. What is it? More importantly, Why is it there?