These creatures are so fragile that the moment they are pulled out from the water, they collapse and disappear.

The Rock Pool Project in Plymouth says the non-native sea hare looks "alien-like".

"You can tell by the 2 frills on its back." Beachgoer captures photo of strange-looking slime creature found on beach: 'Single fleshy mass' first appeared on The Cool Down.

Add Yahoo as a preferred source to see more of our stories on Google. Sea creatures have adapted to help them thrive in extreme environments. Unusual features allow them to live thousands of feet ...