Giantboy is an alternate form of the Player in Dial H for Hero: The Videogame.
After the protagonist in Dial H for Hero finds the H-Dial, a mysterious artifact, in an alleyway, they see it has four letters: H, E, R, and O. After dialing all four letters in that order to spell out "HERO", they find themselves transformed into Giantboy (however they soon learn how to transform into other forms). In the first level of the game, the player must control Giantboy to help stop a car chase, in which the police are pursuing a getaway vehicle.
Giantboy is a black-haired young man wearing a yellow and green sports jacket with a "G" emblem on it. He has a golden motorcycle helmet on and black gloves, as well as a silver belt, green pants, and black boots. When he grows giant, his clothes grow with him.
- Size Changing - The player can make Giantboy either grow to giant size or shrink back to his normal size, depending on which state he's already in.
- Super Strength - While giant, Giantboy has super strength and can lift up all sorts of heavy objects, ranging from people to vehicles.