Bootsie Barker Bites

``My mother and Bootsie Barker's mother are best friends,'' begins the diminutive narrator of this uproariously illustrated story. Bootsie stops short of actually biting, but she bares her teeth in a gleeful lethal grin as the daily mom-and-daughter visit begins. Wearing her broad-brimmed black hat and wickedly pointy hot-pink boots, Bootsie ignores all injunctions to ``play nicely, girls!'' She pretends to be a hungry dinosaur, tears up her timid host's book about turtles and knocks over an aquarium housing Charlene the salamander. Alas, the girls' parents are blind to Bootsie's malevolence and plan an overnight stay; the narrator, certain that she and Charlene will be ``rushed to the hospital with dinosaur bites,'' confides her fears to her mother, whose calm response plants the germ of an idea. The next day the beleaguered heroine thinks fast and gives Bootsie a witty comeuppance. Bottner ( Let Me Tell You Everything ) smoothly adopts the understandably anxious child's point of view, while Rathmann ( Ruby the Copycat ) contributes formidable, hyper-bright watercolors that echo the story's nightmarish but hilarious exaggeration. Ages 4-8. (Sept.)