13 of the ugliest animals on the planet

The ugly stick of evolution

Not every animal is as cuddly as a giant panda or as extravagant as a peacock, but every animal has its role to play and every organism is important.

As they say, beauty is only skin deep. Let's hope — for the sake of these 13 unsightly animals — that the same can be said for ugliness.

This story was originally written in September 2010 but has been updated with additional information.