It is a truth universally acknowledged that a provocative scientific idea will, before too long, end up in the hands of villains that must be fought by superheroes. Witness Boltzmann brains. Sure, they've already made a cameo in Dilbert, but the stakes were pretty low. Now Jim Kakalios (author of the excellent The Physics of Superheroes) sends along sends along a couple of snippets from The Incredible Hercules #133 -- in which our intrepid protagonists are attacked by freak observers fluctuated out of thermal equilibrium!
Actually here they are described as "freaky observers," rather than the more conventional "freak observers." That description brings to mind Smoove B rather than Ludwig Boltzmann, but who knows? Maybe unlikely thermal fluctuations tend to be pretty kinky.
And yes, before you all start in: we know that Boltzmann Brains don't really make for a credible alien menace, if you insist on being persnickety about what they supposedly really represent. It's not that they "perceive" a universe more chaotic than ours -- it's that they would dominate the total number of observers if the universe really were more chaotic than ours. (Which it isn't!) Also, they would tend to dissolve back into the chaos from which they came, rather than staging a coordinated attack on our homeland. Still! What a novel challenge for the Allies' greatest hero.