why do some draenei look different?

[:1]Why do some of the draenei, notably shaman trainers, look completely different from their kin? No real nose, tentecals coming out of back, a "drooping" face, etc|||They are mutated Draenei, called "The Broken". There are some that are even more mutated/devolved called the "The Lost Ones".

When demons assaulted Outland, the Draenei who were caught up in the attacks were sometimes afflicted with demonic taint, which caused them to mutate. The story, Unbroken (which can still be found on wowwiki, can't seem to find it on battle.net), details some of the lore and the personal story on the shaman trainer in the Exodar.