— Commenting on Lucky's scars, Unknown Story
The Heavy King is a character set to appear in an unknown installment of The Legend of Fox the Brave. While genderless, it is referred to as male. Currently, it makes a minor appearance in Vengeance of Night, when the Heavy Magician reports to it after finding the Dire Wolf Pack's camp. As of yet, his goals are unknown.
The Heavy King retains his appearance from Sonic Mania and its add-on Sonic Mania Plus.
While not given much personality in the game, the Heavy King is described on the Sonic News Network Wikia as being cold and authoritative, to the point that he could command the Heavy Gunner with a simple glare. He largely maintains this in The Legend of Fox the Brave, as he commands extreme loyalty from the Hard-Boiled Heavies, but he is willing to acknowledge what he views as impressive aspects of his opponents, believing Lucky wasn't weak when he takes note of the coyote's scarred pelt.
The Heavy King's past in The Legend of Fox the Brave is unknown, but it is implied that some time after Metal Sonic was destroyed by Zero the Zeraora, the Heavy King took over as commander of the Egg Fleet in Eggman's absence, as he states that he won't have the other Heavies fail like Metal Sonic did.
His powers are unknown but possibly the same as in Sonic Mania.
The Heavy King possesses incredible strength and can wield his scepter similarly to a bō staff in combat, able to send Lucky staggering with a single blow to the head.
The Heavy King appears to have very strong leadership skills, as he is able to command incredible loyalty from the Hard-Boiled Heavies.
The Hard-Boiled Heavies
The Heavy King commands incredible loyalty from the Heavies and does not tolerate failure, seen with his meeting with the Heavy Shinobi after it tries to kill Tundra Smith's returning patrol, but Splash the Greninja interferes.
It can be implied that the Heavy King will acknowledge worthy opponents, as he recognizes Lucky has been in battle before when noting the coyote's scars.
- "I will not tolerate failure. Metal Sonic has already failed and received his punishment. Unless you wish to suffer the same fate, do not fail me again."
- —Reprimanding the Heavy Shinobi, Trouble in the South (Epilogue)
The Heavy King is the second Classic Sonic enemy to appear in the series, after the Heavy Magician, who is one of his lackeys.
He is also the first-seen Heavy to not be shown insane in any way, the second being the Heavy Shinobi.