Emrakul is based on fictional Titan of Corruption, the largest and most fearsome of the Eldrazi. She does not affect inorganic matter - rocks, water, etc. - but twists all things living, be they plants, animals or other sentient beings. She causes silent terror wherever she soars, embodying desolation, emotional and physical distance, the chill of the void, and the terror of being alone.

The Emrakul lineage is characterized by flesh-like lattice structures, uneasy bilateral symmetry, and tentacles that end in knobby, vestigial digits. Looking like spongy, alien baleen, the lattice respires independent of the Eldrazi herself, supporting a host of unseen mite—creatures within. Some within this lineage, including Emrakul herself, float above the ground, using unknown powers to alter the surrounding gravity.

This passage was lifted off the MTG Gamepedia.