Hamamatsu Monster is a cryptid reported from Hamamatsu, Shizuoka, Japan.
On May 8, 2008, a person with the handle "nobatakumino" found a dead marine creature on the beach in Hamamatsu and shot a video, which was published on May 15, 2008.（https://youtu.be/7FzPzMhDZe4?si=y_2mEg9DwI-If8bR）
The exact size of the creature is unknown, but it is estimated to be less than 2 meters long. Its skin is decomposed and sunburned, and its original color is unknown. The head is damaged and teeth are visible through the lower jaw. It had the same vertical caudal fin as dolphins.
The identity of this creature is certain from the orientation of its caudal fins that it is a dolphin or whale, and is thought to be either a right whale dolphin, finless porpoise, or pygmy sperm whale.