On a stormy night in a creaky house Grandpa remembers a childhood fright. ""But that's a story too terrible to tell. It might scare the pants off you""--a sure-fire come-on to his grandson, who begs him to tell. And so we hear of a bag of bones in a deserted shack. . . of a young Grandpa's reassembling them until a skeleton takes form and gives chase. . . of the cave to which Grandpa flees and of the witch inside it who turns him into a spider like the many others that dangle about. . . and of the disembodied hand that snatches him off to his next adventure. Then it's out of the ghost's hand and into a wolf's belly for Grandpa, who still has the witch's wishbone and so wishes himself home, ""here and now."" Grandpa's nonstop tall tale won't scare the pants off a spider, but it should whip any audience into a Halloween mood in no time. And there's a lot of lip-smacking, ghoulish energy in Flora's cartoons.