Just in case you were worried that the world of Teen Wolf might get a little too safe and secure, the MTV drama is throwing a new monster into the mix.

Doug Jones (Hellboy, Falling Skies) will appear this season as a “known killer” named Barrow, TVLine has learned exclusively.

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Though other details about the mysterious murderer are scant, we know he’ll show up in Episode 15, which is titled “Galvanize” and which will air after the series returns from hiatus on Jan. 6.

Jones’ history of playing creepy characters includes TV’s The Outer Limits, The Neighbors and Falling Skies — and Buffy fans will be psyched/spooked to know he played one of The Gentlemen in the Season 4 installment “Hush.” In addition to the Hellboy films, his film work includes Pan’s Labyrinth and Fantastic 4: Rise of the Silver Surfer.

Teen Wolf‘s midseason finale airs Monday, Aug. 19 (10/9c).

Got theories on what brings Barrow to town? Shout ’em out in the comments!