As far as ugly creatures go, in my book there is a definite winner--the aye-aye. I think it is the long fingers and huge eyes that creep me out the most. They live in the rainforest of Madagascar in nest made of twigs and leaves. These nests are giant balls with small a small opening as the entrance/exit. They only leave the nests at night to go look for food. When they do venture out of their nests they still spend most of their time in the trees looking for bugs under tree bark. Aye-ayes find these guys by using echolocation and are the only mammals known to do so. They also eat fruit and use their freakishly long fingers to scoop out the fleshy fruit insides.
In Madagascar they are thought to be bad luck (it apparently brings death) so there has never been a fight to protect them by the natives. They are now endangered and the government has finally protected them under the law. A strange thing about the aye-aye is that it seems to be unafraid of humans, even in the wild. They aren't usually a social animal and tend to live alone so it is unnatural for them to be so comfortable around other animals. 




http://animals.nationalgeographic.com/animals/mammals/aye-aye/