Da-Fuze (Raven Starfire Jinx)
http://da-fuze.deviantart.com/art/Ma...keys-595598091
Dragon-FangX
Before
http://dragon-fangx.deviantart.com/a...l-to-285242774
After
http://dragon-fangx.deviantart.com/a...nkey-288056860
After after
http://dragon-fangx.deviantart.com/a...Pets-288207222
http://dragon-fangx.deviantart.com/a...ning-277340797
http://dragon-fangx.deviantart.com/a...nkey-280517454
There was an episode of Stargate SG1 called "The Broca Divide", where a virus caused people to devolve to a fairly primitive state, not ape or monkey level though. One female officer showed cavewomanish behaviour, though you only saw the full physical effects on the men mostly if I remember correctly.