Pilkey's series about a little blue dragon who keeps house (Dragon's Merry Christmas, 1991) gets stronger with each entry. Here, Dragon takes in a cat on a snowy day, then has trouble teaching her the things she needs to know: a sign reading ``roll over'' means nothing to her, and her ``yellow puddles'' are ``smelly'' (there's a particularly funny picture of the obliging cat peering out of the toilet she's trying to use). The mailmouse suggests a litter box, but roadside litter proves to be even smellier. A trip to the pet shop helps to straighten Dragon out; then Cat produces kittens, with still more amusing results. Never a dull moment here; the amiable Dragon's misapprehensions are as much fun as his quirky problem-solving, while the lighthearted illustrations display an unusual sensitivity to color and design in their artless-seeming background detail. (Easy reader. 6-8)