Margaret and Nick Flippence made the incredible find as they exercised their dogs at Bridge of Don, Aberdeen.
Mr Flippence, 59, who lives nearby, said: ‘We were stunned. I thought, “oh my God what is it?”
Monster discovery: Margaret Flippence with the 30-ft long sea creature she saw at Bridge at Don, Aberdeen
What is it? Experts believe the carcass could have been a killer whale or a pilot whale
‘It’s like nothing we have ever seen, it almost looks pre-historic,’ he told the Sun.
Curled up by the foot of sand dunes was the 30ft-long body of the unidentified animal with head, tail and teeth all discernible.
Experts are now examining the pictures with one suggesting it could be the body of a whale.
Whale of a time: A marine life expert suggested the body could belong to a killer whale, above, or a pilot whale, below
A spokesman for the Natural History Museum said: ‘We have spoken to one of our mammals curators, and they have confirmed the animal is probably a long-finned pilot whale – Globicephala melas.
‘Apparently it’s not unusual for these to wash up on the shore.’
Rob Deville, a marine life expert at London Zoo, said the body could be that of a killer whale or a smaller pilot whale.
Whale expert Mark Simmonds told the Sun: ‘it died a long time ago and tides caused the body to wash ashore.’