One way you can tell that you're reading a good fantasy series is that there's a whole world of other stories outside the main one. 
 Such is the case of "Tales of the Peculiar," which expands the world of "peculiar people" featured in the Miss Peregrine's Children series. Rather than a true sequel or prequel, Ransom Riggs spins up long-ago-and-far-away tales of peculiars throughout history, which feel a bit like lost fables or fairy tales. Except way, way, way more twisted, amusing and sometimes gruesome. 
 Among the peculiars examined in the book are: 
 *A village of peculiars with a very specific ability, who are visited by a wealthy band of law-abiding cannibals, who have a very odd proposition for them. 
 *A princess who finds that her serpentine peculiarity makes it hard for her to get a husband. Will her father's cruelty and a lack of a prince ruin her life, or will she be able to forge a new one on her own terms? 
 *The tale of the first ymbryne, a young goshawk with the odd tendency to turn into a human. As she tries to find a place in the human world, she discovers the peculiars -- and the powers she can use to protect them. 
 *A girl who pulls threadlike nightmares out of people's ears, only to discover that nightmares never actually go away.... and they can get mean. 
 *Zheng tries to distance himself from the legacy of his sea-mad father, until suddenly grass grows on his feet, seaweed from his armpits, and he starts sweating sand. And what he learns of his father's fate is stranger than he could imagine. 
 *And stories of birds in a cathedral, a woman who speaks to ghosts, a young boy with a heart too large for his body, a young man who can control the currents of the sea, and a fairy tale of "once upon a peculiar time" where a giant is cursed by a witch. 
 "Tales of the Peculiar" is the kind of book that one can imagine Miss Peregrine having on her bookshelf. It's mostly stories of a fairy-tale-ish nature where a peculiar runs across some kind of disastrous scenario -- sometimes it's intolerant normal humans, or other peculiars, or just their own nature -- and eventually discovers their own special place in the world. 
 And with that style of storytelling, Riggs also writes the various short stories in a different style as well. Most of the stories are introduced with some variant of "Once..." or "There was...", and presented in a more distant way, especially since the tales are occasionally interrupted by an editor's note. But he includes plenty of striking emotional scenes and dialogue ("she was gripped by a sudden wild happiness"). 
 The peculiarities are so varied and sometimes bizarre, ranging from X-Man-esque superpowers to involuntary cannibalism to changing into inhuman forms, that the story possibilities are almost limitless. And in the long-ago-and-far-away settings (medieval kingdoms, Irish villages, enchanted forests, imperial China, the American frontier), Riggs also incorporates an unapologetically macabre aesthetic. I mean, the first story in the collection involves wealthy cannibals, and other stories include amputation, nightmare-monsters, venom-spitting and a guy turning into a giant weeping slug. 
 "Tales of the Peculiar" is a pleasant accompaniment to the Miss Peregrine series -- and though rather different in style, the imaginative stories of peculiar people are pretty entertaining.