In this congeries of magical, mischievous beings, variously pictured and described, there are some apt imaginings: opposite a blowsy, gap-toothed femme--""The Tooth Fairy's teeth fall out. She plants them back in but they pop loose. She can eat only crackers and milk or mashed potatoes. She will pay for your teeth in gold."" Or, in tiny print captioning a tiny, peephole drawing: ""A Gremlin is a tiny imp whose only purpose is to cause mischief."" But many a time the drawing says nothing in particular, nor does the text make it click as an image. Sometimes there's no specific visual or verbal image (""In A Midsummer Night's Dream William Shakespeare plays with love and jelousy, creating a fairyland where the tiny and beautiful Queen Titania and King Oberon make sport with their magic. . .""); other conceptualizations are literal, banal--the embarrassingly hopped-up Ariel and earthbound Caliban; the ""Guardian Angel,"" composed of golden sheaves, who ""glows with golden goodness."" (""As it carries your hopes on its golden wings,"" moreover, ""it will win against all the creatures of the dark and leave a golden trail of peace behind its flight."") Where the pictures are concerned, the imaginary animals or creatures--the Imp of the Perverse, the Black Dog, the Demon of Energy--are more satisfactory than the people. (Then we hear, thuddingly, that the Demon of Energy ""energizes us all; we thrive on its exertions."") For youngsters, no match for the Hosie books or Baskin's other elaborations on natural history.