Excalibur Sonic is the form that Sonic the Hedgehog takes on at the end of the game Sonic and the Black Knight. Using the power of the game's "Sacred Swords," Sonic dons a golden suit of armor, which includes a red cape at the rear. The power from the transformation also regenerates the damaged sword, Caliburn, transforming it into Excalibur.
The form is most similar to Darkspine Sonic, as Sonic is no more impervious to damage than he normally is. He gains the ability to fly, as well as enhanced speed. The form does not depend on Rings, so it will not revert during gameplay. It is only available for play in the battle against the Dark Queen. This transformation is more of a transformation for Caliburn the Sword, as Sonic is still his normal blue self under the armor.
| Characters in the Sonic the Hedgehog game series
||Sonic (Super, Hyper, Darkspine, the Werehog, Excalibur) | Tails (Super) | Knuckles (Super, Hyper) | Amy Rose | Cream | Big | Blaze (Burning) | Emerl | Silver (Super) | Marine | Lumina Flowlight | Chip | Shahra | Knights of the Round Table | Caliburn | Yacker | Sticks | Avatar
||Shadow (Super) | Rouge | Espio | Charmy | Vector | Mighty | Ray | Chaos (Perfect) | E-102 Gamma | E-123 Omega | Bean | Bark | Jet | Wave | Storm | Shade | Merlina
||Dr. Eggman | Metal Sonic (Kai, Rocket, Neo, 3.0) | Mecha Sonic (Super) | Fang | Witchcart | Battle Kukku Army (15th, Speedy, Dr. Fukurokov) | Tails Doll | Metal Knuckles | E-Series | ZERO | Void | Biolizard | Gemerl | Eggman Nega | Black Doom | Angelus | Iblis | Mephiles | Solaris | Erazor Djinn | Captain Whisker | Johnny | Master Core: ABIS | Ix (Super) | Dark Gaia | King Arthur | Orbot | Cubot | Deadly Six (Zavok, Zazz, Zomom, Master Zik, Zeena, Zor) | Hard-Boiled Heavies | Infinite
|| Sonic/Heroes | Rose | Dark | Chaotix | Babylon
|| Gerald & Maria Robotnik | Froggy | Chao | Omochao | Cheese | Chocola | Vanilla | Tikal | Pachacamac | E-101 Beta | Illumina | President | G.U.N. Commander | Elise | Duke of Soleanna | Coconut Crew | Vikings | Professor Pickle | Wentos | Don Fachio | Heavy and Bomb | Tiara Boobowski | Honey | Flicky | Animals | Wisps