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The (male) Fiddler Crab is a famous example of an animal whose morphology exhibits neither mirror nor radial symmetry:

enter image description here (Image source)

List of animals featuring external asymmetry is a Wikipedia article showcasing a few more animals with this property.

Is there a comprehensive list of all such animals that have been described?

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Many(all?) sponges are asymmetrical. – biogirl Jun 26 '14 at 2:22
I don't think that there is a list yet for all but I could probably help you with a few if that is ok. – The Last Word Jun 26 '14 at 7:19
Any that are not on the Wikipedia list would already be helpful :) – pew Jun 26 '14 at 17:28
I am asymmetrical. My right hand is bigger than my left. :) – J. Musser Jul 18 '14 at 23:21
There is a Wikipedia page called "list of animals featuring external asymmetry" – Remi.b Dec 3 '14 at 3:27

1) Pareas iwasakii has asymmetric mandibles. A few more examples of asymmetric snakes (reference)

enter image description here

Pareas iwasakii skull

2) Camels have an asymmetric penis (reference)

3) You could find quite a few in this article titled Animal asymmetry

Hope that helps. I am sure there are more but these are some I could find.

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