Dog's friends are planning a surprise birthday party for him and they need a little help from Pig and Frog to gather the letters to spell out C-A-K-E. When Duck befriends a Shark, he learns that the letters S and H make the "sh" sound, and everyone else discovers that you can't judge a shark by his sharp-toothed cover. Pig's pie for Bear has gone missing, but Pig has no fears when Detective Sheep is ready to help her follow the letter clues and solve the mystery of the disappearing pie. When Bug can't sleep because he needs to be snug, he and his neighbor, Frog, have to figure out the end of the rhyme: "Snug as a bug in a ..."