Hagfish (AP/Scripps Institute of Oceanography)

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If there's a sea creature more repellent than the blobfish, it's this ghastly specimen, which even scientists have labelled the most 'disgusting' fish on the planet.

To escape predators, the hagfish exudes copious quantities of a viscous slime. That's the nice bit. To feed, it enters its victim through the mouth, gills or anus, and devours it from the inside out. Yep, the hagfish has absolutely no redeeming features whatsoever.

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