Quotation1 The leader of the Hard Boiled Heavies. Commands his elite troop with a watchful eye and a powerful scepter. Quotation2
— Description, Sonic Mania manual[1]

The Heavy King (ヘビーキング Hebī Kingu?) is the secondary antagonist of Sonic Mania. The leader of the Hard Boiled Heavies, the Heavy King is an enhanced version of the Egg-Robo created by Dr. Eggman. Struck with the power of the Phantom Ruby, the Heavy King led his troop into battle against the likes of Sonic the Hedgehog.



Originally an Egg-Robo, the Heavy King only received a makeover when he stumbled upon the Phantom Ruby. Decorated as a mixture between a king and a knight, the Heavy King has a red cape, signifying his rank among the other Hard Boiled Heavies as the leader. His appearance seems to be based of both the "Classic" and "Modern" incarnations of Dr. Eggman (having a cape similar to Classic, but having a chestplate resembling the jacket of Modern), the Heavy King has spiked knee joints and triangular shoulder pads along with red boots with golden forefeet. He also has bronze-colored armor-plating on his chest with a white crown symbol. He also has gray appendages and red eyes.



The Heavy King with his elite troop in Green Hill Zone shortly after transforming.

The Heavy King was originally an elite Egg-Robo who handled the most extreme tasks for his creator, Dr. Eggman.[2] After detecting a mysterious energy source on Angel Island, Eggman sent the Heavy King and his Hard Boiled Heavies to investigate.[3] Upon reaching Angel Island, he and his troop excavated the energy source, the Phantom Ruby, just as Sonic the Hedgehog and Miles "Tails" Prower arrived. The Phantom Ruby promptly warped space-time around them,[3] transforming the Heavy King into his royal-esque attire along with his troop. As a side effect of the ruby, the Heavy King and his team gained free wills and personalities of their own, though they were driven mad in the process.[1]

Hard Boiled Heavies Green Hill Act 2

Eggman attempting to command the Heavy King and the Hard Boiled Heavies.

The Phantom Ruby transported the Hard Boiled Heavies, along with Sonic, Tails, and a nearby Knuckles the Echidna, to the Green Hill Zone, where the troop fled with the gemstone. After that, the Hard Boiled Heavies planned to keep the Phantom Ruby for themselves. The Heavy King and his troop soon met Eggman again though, who tried to command the group. When they would not listen though, Eggman snatched the Phantom Ruby from their clutches. The Heavy King and his troop then fled the scene.

Some time after, while the Heavy Rider was preoccupying Sonic and Tails in Lava Reef Zone, the Heavy King took this chance to steal the Master Emerald, but not before Knuckles could arrive. Remembering how Dr. Eggman managed to steal the Master Emerald via a similar manner earlier, Knuckles proceeded to attack Heavy King before he could successfully steal it, knocking him off the crane hook. Even when using the power of the Master Emerald to fight the echidna, the Heavy King was still defeated by Knuckles, who smashed his scepter, and retreated.

Egg Reverie Heavy King vs Eggman

The Phantom King and Eggman fighting over the Phantom Ruby.

When Sonic and Eggman were sent to Egg Reverie Zone with the Phantom Ruby, a powered-up incarnation of the Heavy King known as the Phantom King arrived and swiped the Phantom Ruby and used it to power himself. However, the Phantom King met resistance when Eggman (with the Klepto Mobile) and Super Sonic fought him separately for ownership of the Phantom Ruby. At the end of the conflict, the Heavy King was seemingly destroyed by Super Sonic, failing at his goal at harnessing the Phantom Ruby.


Compared to the other Hard Boiled Heavies, the Heavy King gives of the impression of a brooding, stone-cold authority figure, a complete opposite to the more flamboyant members of his troop. Strict and serious, he rules his troop with an iron fist. With just one look, he is able to command his troop, as seen when the Heavy Gunner immediately followed orders with just one glare from him. He keeps a watchful eye on his colleagues,[1] implying he is extremely alert of a situation. Like the other Hard Boiled Heavies, he wishes to do harm to Sonic, Tails, and Knuckles whether it be by orders from Eggman or by his own, chaotic nature.

Powers and abilities

The Heavy King displays a sheer level of authority, commanding his troops with just a simple glare. He can also fly at will and is more durable than the average Egg-Robo. Also, after coming into contact with the Phantom Ruby, the Heavy King gained the ability to absorb and manipulate energy, as shown during his battle with Knuckles where he would absorb energy from the Master Emerald and then channel it through his scepter.


The Heavy King possessed a powerful scepter[1] that could fire purple lasers and conjure up spheres of powerful energy which the Heavy King could control telekinetically. With power provided from the Master Emerald, its laser could cause explosions and its energy spheres would be arranged into a shield. However, this scepter was broken during the Heavy King's fight with Knuckles.

Phantom King

Main article: Phantom King

In the Egg Reverie Zone, the Heavy King appeared in a new form called the Phantom King.[4] In this form, he gains a massive power boost when harnessing the power of the Phantom Ruby, enough to bypass a Super State user's invulnerability with his most powerful attacks. The powers he command in this form includes flight, increased strength, and scepter-free energy manipulation.


The Heavy King is one of the two final bosses for Lava Reef Zone (the other being the Heavy Rider) and the twentieth overall boss of Sonic Mania. He is fought with Knuckles the Echidna at the end of Knuckles' version of Lava Reef Zone Act 2,

Boss guide

This boss battle will be initiated after Knuckles stops the Heavy King's theft of the Master Emerald. The battle itself takes place in the Master Emerald's altar, whose large Emeralds act as platforms. When the battle begins, the Heavy King will attempt to utilize the power of the Master Emerald, similar to Mecha Sonic from Sonic the Hedgehog 3 & Knuckles. He does so by periodically jumping onto the Master Emerald and absorbing some power from it. He will then hover around the shrine while utilizing one of three attacks:

  • Beams: The Heavy King fires two purple beams across the floor with his scepter. These lasers will emit shockwaves on the floor in their aftermaths that will damage the player upon contact. These beams can be avoided though by standing on top of the Super Emerald replicas, or the Master Emerald.
  • Spheres: The Heavy King creates a shield of spheres around himself that will block Knuckles' attacks. He then proceeds to bounce around the shrine while firing his spheres directly at Knuckles. This attack is best avoided by staying on the move.
  • Bullets: The Heavy King fires a barrage of bullets around the shrine. The Super Emerald replicates can be used as covers for this attack however. Occasionally, the Heavy King may use this attack directly after his beam attack.

After launching his attack(s), the Heavy King will retreat to the Master Emerald and repeat his attack pattern. It is during this period that he will be most vulnerable to attacks. He can also be attacked while he is hovering in the air after charging energy. Hit the Heavy King eight times and he will admit defeat and flee. The player can then proceed to the Capsule and finish the Zone.


Title Artist(s) Music Length
Havoc Prognosis Tee Lopes


Sonic Mania Boss 22 - Heavy King

Sonic Mania Boss 22 - Heavy King


  • The Heavy King makes a cameo within Mirage Saloon Zone Act 2 in the form of a painting. The Heavy King's eyes on this painting will stare at the player's current position until they leave the area.
  • Despite having red eyes, the Heavy King's silhouette in the opening animation for Sonic Mania depicts him with yellow-glowing eyes instead of red. However, in the boss fight in Lava Reef Act 2 with Knuckles, his eyes temporarily glow yellow.
  • The Heavy King is the only member of the Hard Boiled Heavies who does not use "Hi-Spec Robo Go!" as his boss theme like the others, instead sharing "Havoc Prognosis" with the Weather Globe in Studiopolis Zone and Gachapandora in Metallic Madness Zone.
  • Through Debug Mode, it is possible to fight the Heavy King in Lava Reef Zone as Sonic and/or Tails.
    • Interestingly, the player's character will still exhibit the same unique animations Knuckles was given in the cutscene before the battle.
  • If Knuckles is Super Knuckles during the cutscene with the Heavy King in Hidden Palace Zone, Knuckles will be Super Knuckles during the flashback he has there too.
  • The Heavy King is a Knuckles only boss meaning he can only be fought with Knuckles.






Opening animation


Mirage Saloon Zone

Lava Reef Zone


Titanic Monarch Zone



  1. 1.0 1.1 1.2 1.3 1.4 Sonic Mania manual scan
  2. Sonic Mania Information Manual (22 July 2017). Retrieved on 23 July 2017.
  3. 3.0 3.1 Sonic Mania manual scan
  4. Live Sonic Mania Developer Playthrough (5:49:13). Stealth (20 August 2017). Retrieved on 22 August 2017.

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