20th Century Fox may be adding another antagonist to its 2015 "Fantastic Four" reboot: The Hollywood Reporter said Wednesday Tim Blake Nelson is in "final negotiations" to play Harvey Elder, better known in Marvel Comics lore as the Mole Man.

According to THR's sources, Elder will appear in the upcoming film as "an eccentric and socially awkward scientist," not in full supervillain mode, though the reported plan (which Fox declined comment on for THR's report) is for the character to return as the Mole Man in subsequent installments. Toby Kebbell has already been cast as the film's Doctor Doom.

The Mole Man actually predates Doctor Doom as a Fantastic Four villain, having first appeared in 1961's "Fantastic Four" #1 by Stan Lee and Jack Kirby. Nelson, who appeared earlier this year on Discovery Channel's "Klondike" miniseries, has prior Marvel-based comic book movie experience -- as Samuel Sterns, the would-be Leader, in 2008's "The Incredible Hulk."

Directed by Josh Trank and starring Miles Teller as Mr. Fantastic/Reed Richards, Kate Mara as the Invisible Woman/Sue Storm, Michael B. Jordan as the Human Torch/Johnny Storm and Jamie Bell as the Thing/Ben Grimm, "Fantastic Four" is scheduled for release on June 19, 2015.