Sheik

A mysterious warrior with great wisdom and strength. Sheik is a Sheikah, as revealed when he first confronts Link in the Temple of Time. He describes himself as the last remaining survivor of the Sheikah tribe. Sheik helps Link along his quest while he never reveals who he is and why he is aiding Link. His advice and knowledge of the world make him a great ally in the Link's quest.

Soundtracks/Themes
Every appearance Sheik has made in Ocarina of Time is accompanied by a melodic tune played by the harp. Titled Sheik's Theme the theme is composed by Koji Kondo and is featured in the official game soundtrack.

Super Smash Bros. Melee
In Super Smash Bros. Melee Zelda has the option of transforming into Sheik. To do this, you must press down the analog stick with the B button. Sheik has a completely different moveset than Zelda. Sheik's moves and weapons are quick and similar to those of a ninja. Sheik is an extremely speedy character and for this reason she could be a bit difficult to control. Although she has an original moveset, she is found to have similarities with Captain Falcon. In Melee the two of them have a more powerful star rod attack. In the game, Sheik is always referred to as a female.

Super Smash Bros. Brawl
Sheik has been confirmed for the sequel to Super Smash Bros. Melee, Super Smash Bros. Brawl. Although she did not appear in The Legend of Zelda: Twilight Princess, the character model was based on a design drafted during the game's development. She has mostly the same moveset from Melee, and shares a Final Smash with Zelda, the Light Arrows.

Gender Issues
It is later revealed in the game, that Sheik is actually Princess Zelda. This would suggest that Princess Ruto's remarks about Sheik's gender are erroneous and that she was not aware of her true identity.

Various fan theories exist concerning Sheik's true gender, but the one most supported by evidence from OoT itself is that Sheik is Princess Zelda in a masculine disguise. In Super Smash Bros. Melee, Sheik's profile describes the warrior as being "she". But, if you read the Japanese strategy guide, it explains that she used magic to literally turn herself into a boy...

However, considering that Sheik was nothing more than a character, designed by Zelda to hide her true Identity, Sheik's identity would be whatever Zelda was trying to appear as. As the clothing is mainly male, Sheik can be said to be male.