Montauk Monster
The Montauk Monster was the corpse of a dog-like organism, which had washed up on the shores of Montauk during July of 2008. The creature made global headlines when it was discovered due to its bizarre appearance. Most of the corpse's fur had already rotted away but the time it had been discovered, and its skull had weathered away into a beak like point.
It's appearance seemed largely unsuited for a marine lifestyle, so it was quickly deduced as being a washed up corpse rather than an oceanic organism. Conspiracy theories would eventually rise that the Montauk Monster was an experiment from the Plum Island Animal Disease Center, infamous for conspiracies related to alleged involvement in bio-weapon research. More skeptical explanations for what the cadaver might have been included; a small sheep, dog, coyote, or other medium sized mammal.
Most scientists, and cryptozoologists alike today believe that the creature was in fact a raccoon that had died elsewhere and simply washed up on the shores naturally due to ocean currents. Whilst the original cryptid has long since been identified; the idea of the Montauk Monster still somewhat persists in the worlds of pop culture and cryptozoology as its name is still sometimes used to describe all sorts of mammalian globsters that wash up on shorelines.