They might be fearsome demonic creatures, riding hellish steeds on a morbid quest to find and slay the ring-bearer, but you'd better not get them wet. Presumably there's a lost Tolkien appendix somewhere that says Nazgul are like Gremlins, and establishes the rules relating to water and feeding after midnight.
23. The Avengers
Wait, so Loki actually likes kids? Who'd have thought that between diabolical plans to take over Earth and ruin his brother, the demi-God superhero hires himself out as a climbing frame to toddlers.