M'tokra was the Klingon father of Sorval, an alias used by Worf.
In 2372, Worf introduced himself as Sorval, son of M'tokra, to a Klingon lieutenant when he and Kurn boarded the IKS Drovana. (DS9: "Sons of Mogh")
It is unclear if either Sorval or M'tokra actually existed.