Methushael
Methushael is a descendant of Cain, four generations removed, and the father of Lamech. Genesis 4:18 records the line: "Irad begot Mehujael: and Mehujael begot Methushael; and Methushael begot Lamech." UPDV uses the spelling Methushael throughout.
He belongs to the line that runs Cain → Enoch → Irad → Mehujael → Methushael → Lamech, the Lamech who took two wives and composed the taunt-song of Genesis 4:23–24. No other details about Methushael are given in the UPDV text.