Certain guys just have that look. No matter how hard they try to conceal it with smiles and positive energy, some guys have an inherently menacing appearance.
Take Willem Dafoe, for example. Although he seems like a fairly chill individual, Dafoe looks like he was born to always play the role of a villain or anti-hero. I guess that's why so many Cinephiles and Batman fans have been clamoring for Dafoe to play the Joker one of these days.
Michael Shannon is another actor that can't escape his menacing look. At a glance, Shannon looks like the type of guy that you wouldn't want to run into in a dark alley. However, if you were to run into Shannon in the aforementioned alley, he'd probably have a warm conversation and some solid film recommendations ready for you.
In the video linked above, you can check out Michale Shannon's top picks from the famed Criterion closet.