Kappa

A Kappa is a helpful water creature, originating in Japan. It protects humans in exchange for food.

History
Originally believed to be attacking the people in a small town, Sam and Dean happened to be stuck in. The brothers investigated and thought it was an aquatic demon called a "Yam" but after more investigation it was uncovered that creature was not harming anyone, it was actually saving lives. It had protected a couple from a car accident, saved a man from a fatal heart attack and saved a group of hunters from both a landslide and a lightning strike. It took food from all the people its saved and had a particular fondness for sweets. After Sam tells the towns people that the creature was actually helping them, they all agree to stop hunting it and let it be free.

Powers

 * Danger Sensing: it can see future events that would cause humans harm,such as a landslide, lightning strike and a car accident. It was even able to see that a man was going to have a fatal heart attack.
 * Underwater Breathing: It lives and thrives underwater but can walk on land.
 * Longevity: the creature was well over 100 years old
 * Super Strength
 * Super Speed

Appearance
It was Covered in scales, and had webbed hands and feet with sharp claw like fingers. Humanoid but turtle and frog like in appearance. It had big eyes and a large toothy smile