Lon Chaney, Jr.
Lon Chaney, Jr., as all his many fans know, was not Lon Chaney, Jr. In fact, he didn't even want to be Lon Chaney, Jr.
But he was the son and only child of Lon Chaney, Sr, and Lon, Sr.'s, wife, Cleva.
As for sorting this conundrum, you can, if you wish, read the authoratitive autobiography of Lon, Jr. Or you can find learnèd articles about his life and work.
Or you can click here.