Slith
The Slith are mysterious creatures from Mirrodin. They are born within Kuldotha, the Great Furnace, and only emerge when one of Mirrodin's suns are aligned overhead. As they emerge, the Slith's attributes are set according to whatever sun was overhead. Afterwards they continually follow the motion of their aligned sun. They resemble hunched human forms with skull-like faces. Unlike other Living things on Mirrodin, Slith have no metal on their bodies, implying that they are resistant to Mycosynth. The Slith cards were all based on a card with a similar effect called Whirling Dervish (Whirling Dervish).
(Slith Bloodletter)
Read more about this topic: List Of Species In Magic: The Gathering