Globster

A Globster or Blob is a supposedly "unidentified" lump of rotting sea creature flesh and is often used as "proof" of all manner of things. It's the Cryptozoologic equivalent of a UFO: "I don't know what this mysterious unidentified thing is, therefore it is proof of sea serpents, giant octopuses, or cthulhu". After people who actually know what they're talking about take a look at these "globsters", they're invariably proven to be the carcasses of basking sharks or rotting mounds of rancid whale fat.