Sinbad is essentially a doppelganger of his mainstream counterpart and is so identical to him in anatomy.
History
Sonic and the Secret Rings
Sinbad and Sonic first met when Ali Baba recommended to seek him out for his advice on how to deal with the Ifrit. At that point, Sinbad had been engaged in a battle with pirates when he was kidnapped by the Rukh, most likely under the orders of Erazor Djinn. Sonic and Shahra then set off to find him.
The duo soon find him held in a cage aboard one of the Rukh, where he understandably requests that he be freed before he shares his advice with them. Sonic soon frees him and Sinbad provides the somewhat obvious suggestion of defeating the fire genie by dousing him with water. He proves he is still just as stubborn as Knuckles when he started to fight with Sonic when the hedgehog insulted his suggestion. After their argument is broken up by Ali Baba, Sinbad elaborates that he meant recovering the Water World Rings he had stolen from the pirates and using that to produce the water needed to extinguish and defeat the Ifrit.
After Sonic had defeated the Erazor Djinn, Sinbad aided him and Ali Baba during Sonic's following adventures as he searched for a way back to his own world.
Personality
Much like Knuckles, Sinbad is aggressive, stubborn, gruff and somewhat antisocial. Likening life to a game of give and take, he is willing to help others out, but only if they do something for him in return. Compared to his counterpart, Sinbad is more intelligent, in terms of solutions to defeat an enemy. Sonic has even attested that Sinbad comes off as a bit smarter than Knuckles, but that it is "not saying much."[1]
Powers and abilities
Weapon
Sinbad wields a yellow-curved dagger with a ruby at the end of the handle. His proficiency with it is unknown.
Quotes
"Life's a game of give and take, see? You free me, and I'll help you out later."
