The Demiurge.
Gnosticism portrays Demiurge as an inferior "evil" god who created the world who appears as the "God" of the Old Testament. The concept of a Demiurge is that it is an artisan figure responsible for the fashioning and maintenance of the physical universe. Even if it's a fashioner, it isn't a creator figure in a monotheistic sense: the demiurge itself and the material it uses to create and fashion the universe are considered uncreated and eternal or the product of another being, depending on the system. The Demiurge is known as Yaldabaoth within the works of H.P. Lovecraft, although it is unknown as to what sort of deity it is, either a Great Old One or an Outer God. But due to its status, it is highly possible that it is an Outer God and thus regarded as one.