Hide-and-Seek Harry is an animatronic toy bird that belongs to Manny Heffley. The only appearance was when Greg was in the boiler room and stated he was hiding. Because Greg Heffley was already scared of the boiler room and thought Harry's voice sounded like a ghost girl, he and Rowley Jefferson, who were having a slumber party in the basement, told Frank Heffley about it, stating that the house was haunted. Frank bumped around in the basement for a bit, and just when Greg thought Frank had gotten killed or something, he came out holding Harry, who said: "Peek a boo!"
- Dog Days - First and only appearance