Hide-and-Seek Harry is an animatronic toy bird that belongs to Manny Heffley. It only appears in Dog Days. He vaguely resembles Preston Platypus.
During Greg Heffley and Rowley Jefferson's sleepover, they slept in the basement and hears noises from the boiler room produced by Harry that sounded like a ghost-girl. They marched into Greg's parents' room and then Frank Heffley looked around in the basement for a bit and found Hide-and-Seek Harry who said "Peek a-boo!".[1]