It helps to have a best friend when you run into trouble, whether it''s the what-to-wear-to-a-party kind or the wildlife-on-your-head variety. Like the first two entries in this beginning reader series (My Friend Is Sad and Today I Will Fly!, rev. 5/07), each of these books features a simple story told entirely through speech balloons and Willems''s emotive pig and elephant characters. The animated illustrations will help new readers decode tone and meaning while the spare dialogue enhances the pictures'' slapstick humor. High-spirited Piggie has never been to a party; when she receives her first invitation, neurotic Gerald takes charge of their attire. "I know parties," he claims, but Piggie and young readers may have doubts about that when Gerald insists they dress for "a fancy pool costume party." In the end, Gerald proves to be savvier than he and Piggie look. In the second book, two "love birds" make a nest on Gerald''s head. Cause enough for panic, but when their three eggs hatch (in record gestation time), hysteria ensues. Luckily, Piggie has a good head on her shoulders. The minimalism of both the text and the uncluttered pictures focuses readers'' attention and moves the stories forward. Party on, Elephant & Piggie!-Horn Book