Late in the third season, we get the cold open for the episode "Product Recall." In it, Jim arrives at work dressed exactly like Dwight. His hair is parted, he has a briefcase, and he's wearing a mustard yellow shirt, brown suit, a watch, and glasses. Even more impressive, he pulled the entire ensemble together for a mere $11.
After settling in at his desk and donning his spectacles, Jim aggressively asks Dwight which bear is best, proactively responding, "False. Black bear." He then follows this up with the Dwight-tailored quip, "Bears. Beets. Battlestar Galactica." As Dwight begins to catch onto the prank, Jim pulls out a bobblehead, clearly mocking his coworker's own collection. This pushes Dwight over the line and sends him into a tirade about identity theft. As the scene ends, Jim shouts for Michael and storms off towards the bosses office, followed closely by his thoroughly perturbed nemesis. The best part? In spite of his disapproval, Dwight will ultimately use a similar tactic in season five, when he gets under Andy's skin by dressing and acting like the Cornell grad.