|Artwork of Cannon/Shield Cannon from Mega Man 3.|
Cannon (or Shield Cannon as it is referred to in Mega Man Powered Up) is a cannon robot. It was originally designed as a defense system to protect against attacking aliens. They are enemies that originate from Mega Man 3 from Needle Man's stage.
When the player is more than 4 tiles away horizontally from Shield Cannon, it will be in its "passive state" where a protective shielding will cover the cannon barrel and protect it from most damage.
When the player is 4 tiles away horizontally from Shield Cannon or less, it will be in its "aggressive state" where the protective shielding will slide away revealing the cannon barrel and will fire two large cannonballs at the player, then briefly covers the cannon barrel with its protective shielding for a few seconds, before looping back to his first behaviour firing two cannonballs again.
When the player is more than 4 tiles away horizontally from Shield Cannon when it is in its "aggressive state", it will return to its "passive state" once its fired its most recent barrage of two cannonballs.
- Shield Cannon also appears in Mega Man Powered Up, Mega Man: The Wily Wars, and Mega Man II / Rockman World 2,
- Due to the way Shield Cannon's AI functions and how it is placed in Mega Man Maker's Level Builder, its manual facing direction is redundant, as it is programmed to always turn to face the player if they are behind it.