Upon completing the Eggmanland stage, Sonic the Werehog and Chip end up in the opening of a canal leading to the core of the planet. Eggman surprises the duo by revealing his latest creation: the new "Ultra-hyper Prototype 1", better known as the Egg Dragoon. The doctor promptly destroys the cover of the canal Sonic and Chip are standing on, forcing the two to seek a foothold on a chunk of metal. After a heated battle, Sonic manages to dislodge Eggman from its cockpit and disable the Egg Dragoon's propulsion system, causing the robot to fall and melt into slag in the planet's core. Eggman then tells Sonic that one day he will build an "Ultra-Hyper Prototype 2", moments before he is attacked by Dark Gaia and sent flying off into the sky.
Though it is unofficial, it appears that Eggman has an early design for the Egg Dragoon used on his Star Cruiser. The torso of the original mech became part of the Egg Dragoon's "head".
The Egg Dragoon reappears in Sonic Generations as the Modern era's main boss. Heavily modified from the original version, this "Ultra-Hyper Prototype 2" version is modeled to outmatch Sonic's running speed, and is capable of displaying a wide variety of attacks while on the run (flamethrowers, freezebombs, drill projectiles, etc.). It has two cockpits: One located in its head, and the other in its lower-belly. Throughout the battle, Eggman toggles between the two sets of controls, attacking using the machine's torso and legs respectively. In addition, this version of the Egg Dragoon can split into two independent robots.
This time, Modern Sonic fights the Egg Dragoon without his Werehog powers.
The Egg Dragoon was one of the most powerful of Eggman's robots. Its thick armor made its body impregnable even against Sonic's attacks, and it possessed a lethally efficient selection of weapons. Its power source was supplied by Dark Gaia.
The Egg Dragoon's weakness seems to be the orb at its bottom, as well as Eggman's cockpit.
Weapons and Abilities
On the Egg Dragoon's right arm is a massive energy cannon. Along the cannon's octagonal carapace, eight small barrels extend outward from the primary mechanism. These cannons rotate independently at great speed, launching a barrage of energy blasts with every spin, similar to that of a Gatling gun. The inner part of this cannon holds an canister of supercooled gas that Eggman launches in a concentrated blast in attempts to freeze Sonic.
On its left arm, the Egg Dragoon holds a long and gigantic drill. With a sideways wave, the drill can release a massive wave of electrical energy at the Werehog. The drill can also be launched like a homing missile at its targets, and can drill through the arena easily. Amusingly, Sonic uses this against Eggman in the QTEs of the fight, since Eggman's drill ends up striking the orb on his machine.
The Egg Dragoon also has wing-like energy protrusions on its shoulders that allow it to hover.
- In Sonic Unleashed, this is the only Eggman boss battle fought as Sonic's Werehog form.
- The Eggman-piloted robot from the introduction of the game is similar in design to the Egg Dragoon.
- If the player fails to defeat Eggman at the final QTE where he is thrown at the end of the fight, the Egg Dragoon will regain health back, but when the QTE is preformed again, the Egg Pod is still heavily damaged, and the cockpit's glass is broken.
- The Egg Dragoon's elemental attacks in Sonic Unleashed seem to give references to the game's other night time bosses; the ice bomb refers to Dark Moray, the fire bullets refer to the Dark Gaia Phoenix, and the electric swing with its drill refers to Dark Guardian.
- In Sonic Unleashed, when the Egg Dragoon is preparing to sweep the platform with the electrified drill, the word "danger" appears at the edges of the area to be swept.
- The Egg Dragoon's power supply in Sonic Unleashed was energy from Dark Gaia; in Sonic Generations, this supply may be obtained from the Time Eater. Though, since the other bosses seem to be temporal distortions where the fight takes place in the same spot it did in its game of origin, the power supply may still come from Dark Gaia due to its being located in the past.
- The portals the Egg Dragoon goes through in the Sonic Generations battle are similar to the ones the Time Eater creates. It is possible that the Time Eater was helping him during the fight, or Modern Eggman infused some of its power within it.
- Due to its appearance in Sonic Generations, the Egg Dragoon is the only boss that is ever fought as both Normal and Werehog Sonic.
- Since it was so heavily modified, the Sonic Generations version of the Egg Dragoon is often considered the Ultra-Hyper Prototype-2, or sometimes the final release 1.0 Dragoon.
- When the music for this battle was remixed for Sonic Generations, the only thing that was changed was the orchestra, which was removed.
- Egg Dragoon could have gotten its inspriation from the boss Magma Dragoon from the Mega Man X4 game, due to both having red as their primary color and being based somewhat on a dragon.
- In the Mobile version of Sonic Unleashed, the Egg Dragoon was the final boss, however it's design was completely different to the one of the 360/PS3/Wii version. Instead of being red and having a small portion of black, it was light blue and had a little bit of orange.