Here she is, boys: the leading identified cause of Guillain-Barré syndrome! Campylobacter bacteria can get into water anywhere that animals might be poopin', so your odds of running into this friend are pretty good (I mean, how often do you see an animal that's not pooping). You'll almost certainly get a fun case of diarrhea, but wait, there's more! The infection is known to sometimes trigger GBS, a rare autoimmune disorder that can leave you permanently paralyzed. Also, some strains of Campylobacter are now resistant to multiple antibiotics. So you might be hanging out with this one for a long time. Best friends 4 ever.