In this beguiling work, a human father and son enjoy a flight of fancy, imagining themselves as bears. Toby wakes to what he thinks is the loud growl of a bear in the house and discovers it's only his father snoring. His father goes along with the idea, however, declaring himself Big Grizzly and naming his son Little Grizzly. They go into their dark den under the quilt, where they eat ``Gummy Bears'' for breakfast and fend off would-be predators. Rosemffet strikes gold by depicting Toby and his father as bears while they are under the quilt, giving readers a window into Toby's imagination. This special moment of togetherness between parent and child is convincingly captured in both text and art. Mom has a nice role, too. (Picture book. 5-8)