TTBM: Buses. Or more specifically, the people on them. I regularly see old crones that can only be described as witches, who constantly insist on taking the spot next to me instead of a free one that isn't. Then there was the grotesquely overweight guy who stank of urine. A smell that was most likely emanating from his pants, which were unzipped either by choice or disintegrated by sheer pressure from the copious amounts of fat it was trying to contain.
I also saw a guy who looked exactly like the grinch, only less green. He had red hair too, so it might have been Satan, I'm not sure.
In any case, buses frighten me now.