Image Source: Getty Images / Roy Rochlin In his run thus far on Netflix’s “Stranger Things,” David Harbour – who plays the beloved Jim Hopper – has become a monster-fighting, lovable parental figure and town hero. In season four, specifically, we get to see Harbour as one hell of a fighting machine. (Seriously, the willpower!) Turns out, that’s not just the work of special effects, great screenwriting, or skilled stunt doubles. According to a recent TikTok posted by Harbour’s trainer, he’s quite a beast IRL, too. The TikTok was first posted on June 8 by “real life superhero trainer” Don . . .