Wonder Boy in Monster LandEdit
Mecha Dragon is the leader of the monsters and the final boss. At first it appears to be a normal dragon, but after Book defeats it, it is revealed to be a robot from outer space. It attacks by releasing powerful flames from its mouth.
Wonder Boy III: The Dragon's TrapEdit
This spin-off starts at the end of Wonder Boy in Monster Land, with Mecha Dragon being the first boss. After its defeat, it casts a curse on Book that transforms him into a Lizard-Man.
- In Saiyūki World, the Dragon was replaced by Kyuu Maou (きゅうまおう), the Bull Demon King (牛魔王). After his defeat, Kyuu Maou "reveals his true form" (しょうたいをあらわした Shoutai wo Arawashita)
- In Bikkuriman World, the Dragon was replaced by Shiso Jura and Mecha Dragon by Black Zeus.