Kwundaar

Kwundaar was the "god" who created the Source for the Trakenites and came from the Pre-Universe. Kwundaar attempted to trick the Doctor into giving Kwundaar its power, he failed and was overcome by it. Before Kwundar was destroyed, he sent out a signal for other Primeval beings to come back into the universe, and marked the Doctor for them. (BFA: Primeval)