This is the largest jellyfish in the world. Specimens 8 feet wide with tentacles 60 feet long have been found. In Sir Arthur Conan Doyle's story, "The Adventure of the Lion's Mane," Sherlock Holmes solves a death caused by contact between the victim and this medusa in a tidepool.

Look For: A saucer-shaped jellyfish that starts out pink to yellow and darkens as it ages and grows to dark reddish-brown or yellowish-brown. Shaggy clusters of more than 150 stinging tentacles hang down below.

Length: Saucer 5" to 8' wide.

Habitat: Ocean surface.

Range: Arctic to Florida and Mexico; Alaska to southern California.