Why is aye aye a magical animal?

Aye aye's aren't magical, they're just funny-looking and that has lead to several negative superstitions surrounding them:

Besides being a general nuisance in villages, ancient Malagasy legend said the Aye-aye was a symbol of death- should an aye aye point at someone with their long finger, that person is cursed to die. The Sakalava people go so far as to claim aye-ayes sneak into houses through the thatched roofs and murder the sleeping occupants by using their middle finger to puncture the victim's aorta.

(paraphrased from wikipedia)