This article, based in the Classic Sonic world, is incomplete.
The Hard Boiled Heavy that became the heavy King was created alongside his squad by Dr. Eggman as a special group of elite badniks. 
At some point in the past, Dr. Eggman created the Hard Boiled Heavies to act as his elite Badniks. After a strange gem (the Phantom ruby) fell into Angel Island, Eggman sent the Heavies to investigate. Upon being exposed to gem's energy, they became more powerful and attempted to rebel against Dr. Eggman. Sonic eventually defeated them. Despite trying to usurp him, Eggman was not unswayed in using them again. 
Seasons of Chaos
Dr. Eggman's Birthday
By harnessing the energie of all seven chaos emeralds, the Heavy king was able to use his sceptre to fire formidable bolts of energy.
Dr. Eggman is Heavy King's creator and master.
- Dr. Eggman
- Hard Boiled Heavies
- Metal Sonic (Classic)
- Metal Knuckles (Classic)
- Sonic the Hedgehog (Classic)
- Miles "Tails" Prower (Classic)
- Amy Rose (Classic)
- Knuckles the Echidna (Classic)
- Dr. Ivo "Eggman" Robotnik (Classic) (formerly)
- Ray the Flying Squirrel
- Mighty the Armadillo
- Fang the Sniper
- The Heavy King, along with his squad first debuted on Sonic Mania.