Ghroth is an Outer God that resembles a rust-colored moon with a single gigantic red eye that it closes to avoid detection. It's made up of molten iron, ash, and gas, and splitting the surface are cracks or faults. Below its crust are vast seas, which are used to form a giant eye.
It drifts throughout the universe while singing its siren song, The Music of the Spheres. Any Great Old Ones or Outer Gods sleeping on a planet it passes is awakened by its call. Ghroth destroys planets as well and destroyed the home of Baoht Z'uqqa-mogg forcing it to flee its home and take up residence on Earth. As Groth gets closer to a world, the planet experiences natural disasters in the form of erupting volcanoes, tidal waves, earthquakes, changing tides, and horrific storms.