Grayskul is an American hip hop duo based in Seattle, Washington, consisting of rappers Onry Ozzborn and JFK Ninjaface.

[2] The duo often collaborate with artists from the Pacific Northwest hip hop collective Oldominion.

[3] In 2003, Onry Ozzborn and JFK, both members of the Pacific Northwest hip hop collective Oldominion, teamed up with bassist Rob Castro to form Grayskul.

They recorded about 55 songs in 8 months at ATB Studios; these would eventually become the albums Creature, Thee Adventures!

[9] While this album excluded Rob Castro,[10] Cage, Slug and Aesop Rock provided guest verses.