I just looked up what might live in bogs, and it includes frogs, bog turtles, muskrats, smooth newts, moose, owls, hares, beavers and salamanders. None of which I particularly want touching me.
Also bog people, which are ancient cadavers which becomes naturally mummified in peat bogs, mostly dating from the Iron Age. Imagine taking a swim in a nasty bog and coming up against someone who is centuries old and looks like a piece of jerky.