Take a Hike - S1.E12

Ned attends Boy Scout camp, and Newton notices that the other scouts have more merit badges than Ned. Ned doesn't care, as he's allergic to the outdoors and doesn't enjoy being a Boy Scout, but not wanting to see his owner disgraced, he motivates Ned to earn as many merit badges as he can. Eventually, when Ned becomes the most decorated Boy Scout, Newton decides to wrap the entire forest in anti-allergenic plastic, but when he does, Ned finds out that he wasn't allergic to anything in the forest, but to his mother's macadamia-nut cookies that she always packs him.