Nutria

Context:  This one needs three background details in order to make the proper amount of nonsense. First: several years ago, I had just moved to Portland, OR, from the Southwest, after a personal rough patch that left me a wee bit sleep-deprived.  Second: during the nineteenth century fur boom, some enterprising soul imported a large rodent called the nutria to the Pacific Northwest, to raise for fur.  Third: at the point at which this occurs, I'd been in Portland approximately four months and, still not having seen one of the little buggers, had begun to insist my family had made them up to pull my leg and that "nutria" was, in fact, a kind of snack bar.

Me (in the passenger seat of Mum's moving car, having just spied a nutria): "There, there was a-! I saw one!" (cue frantic gesticulation)