Yokai: they're sort of the faeries of Japanese folklore, except way way weirder.
Fortunately Hiroko Yoda and Matt Alt do a pretty good job of compiling several of the odder ones in "Yokai Attack!: The Japanese Monster Survival Guide," complete with some intricate and sometimes funny illustrations in a traditional style. And none of the yokai here are watered down -- we have the good, the bad (onibaba) and the disgusting (filth-licker) and the really, really strange.
Among the creatures listed here: the Karasu-tengu, a blobby humanoid with no head and a really offensive stench, the Piggyback Monster, the corpse-devouring Onibaba, demon cats, the chimeric Nue, the sea ghosts, the "Rat Monk," an oni that apparently suffers from OCD, a muddy rice-paddy creature, the scum-sucking Akaname, the creepy little singing Azuki Arai, a tree of human-faced fruit, the tanuki, a woman with a giant stretchy neck, and an utterly freaky girl with a "slashed mouth."
And then there are the REAAAAAALLLYY WEIRD ones like a yokai constructed out of dishes, a second mouth that appears on the back of girls' heads, dozens of eyes in a sliding screen, flying skeletons, the amusing Namahage, a giant disembodied foot, and the Tsukumo-gami (who are basically random household items come to life).
Certainly the Japanese can't be accused of making up boring apparitions and specters, because there's nary a boring moment in this book. A few of the creatures chronicled here have been more extensively covered in various media (such as the kitsune, the tanuki or the kappa) but most of them are relatively obscure -- and freakier than you'd expect. Seriously, who came up with these?
Yoda and Alt write in a pleasantly tongue-in-cheek manner. And they relate lots of stuff about these yokai: the pronunciation and translation of their names, their physical stats, their odd features ("tentacle-like, prehensile hair"), their offensive weapons ("incessant cacophony"), their abundance, their favorite food, and anything else that's relevant. Then they relate more detailed information about what these creatures do and the possible sources of it, as well as weird little cultural tidbits (such as a children's song about tanuki testicles.... ew).
It's also pretty obvious that some of these were either generated as warnings (the Namahage turn up to terrorize whiny kids) or wishful thinking (the Akaname will eat the filth of a poorly-cleaned bathroom, which I'm not going to talk about anymore because it's making me sick). And they have some pretty bizarre stories attached to them which anime and manga might not reveal -- such as the really nasty way that kappas kill people (disemboweling through, er, a personal orifice).
"Yokai Attack!: The Japanese Monster Survival Guide" is a fun look at some very unusual monsters, specters and supernatural creatures, and the book just gets weirder and more fun as it goes on. I only wish it were longer.