Once again, an illustrator finds a novel way to rehearse familiar animals. The blonde tot here imagines her fubsy big dog as a horse pulling her cart, an elephant she can ride, a lion to be tracked, and more; alternate spreads depict first her play activity with the dog, then the scene she is imagining. But the story of Red Riding Hood seems too real (`` `What big teeth you have!' I say. I wish I hadn't come today...I wish I'd stayed at home to play'') and the last of Lacome's boldly childlike illustrations shows her there, ``with Fred,'' who is getting a hug as his very own self. Simple but thoughtfully constructed; just right for the youngest. (Picture book. 2-6)