Superboss

Superbosses are extremely powerful optional bosses that are accessible after completing the game and defeating the final boss.

They are usually far more powerful than even the Final Boss of the game. They are also different from True Final Bosses.

Dragon Quest I & II did not feature any form of Superboss.

Dragon Quest III

Dragon Quest III featured two Superbosses, both added in remakes.

Xenlon was featured as a Superboss in the SNES remake, while the Grand Dragon was featured in the Gameboy Color version, surpassing Xenlon in difficulty.

Dragon Quest IV

Much like III, Dragon Quest IV did not feature any Superbosses initially, but the PSX and DS versions added Chow Mein and Foo Yung.

Dragon Quest V

Dragon Quest V featured Estark as its Superboss. Estark would later appear as a Superboss in several other games.

Dragon Quest VI

Dragon Quest VI introduced Nokturnus as a Superboss.

Dragon Quest VII

Dragon Quest VII had a few Superbosses. Numen, along with the Fire Spirit, Water Spirit, Earth Spirit and Wind Spirit are featured as Superbosses.

Dragon Quest VIII

After defeating Rhapthorne, the party can access the Dragovian Path, where they can encounter the Lord of the Dragovians. After an initial battle in his dragon form, the player can go back and rematch him several times, each time in a different form.

The 3DS remake added an entirely new area, Memories Lane, which had much more powerful versions of all previous bosses. Estark returns and resides at the end of the area.

Dragon Quest IX

Dragon Quest IX features many post-game bosses, including the Legacy Bosses. Legacy Bosses are the previous final (and some Super) bosses from past games. Dragonlord, Malroth, Baramos, Zoma, Psaro the Manslayer, Estark, Nimzo, Murdaw, Mortamor, Nokturnus, Orgodemir, Dhoulmagus and Rhapthorne all appear as Legacy Bosses.

The game also features some powerful DLC bosses.

Dragon Quest X

The King of Calamity appears as a Superboss. He greatly resembles a more demonic Estark.

Dragon Quest XI

Dragon Quest XI features several Superbosses. Upgraded forms of the previously-fought Spectral Sentinels can be fought at Trial Isle.

In the 3DS and Definitive versions, monsters that resemble previous Final Bosses appear as Superbosses. Defeating them will allow the party to face off against the End of Time.

Defeating the End of Time will grant access to an even stronger Superboss, the Timewyrm.