The Spy (real name unknown) is a French mercenary employed as an assassin by Reliable Excavation Demolition and/or Builders League United. He is a tall and thin man with a thick French accent wearing a classy suit, a tie, and a mask (all of them red or blue depending on the situation, although he is traditionally more represented in blue).
He uses a variety of weapons and high-tech accessories to complete his objectives. He is a known master of disguise, though a trained eye would notice that he is actually wearing a piece of paper with a face drawn on it as a mask. He also has electric jammers called Sappers and a variety of cloaking devices hidden in watches; one of them, the Dead Ringer, allows him to fake his own death on the battlefield. He fights with his signature butterfly knife (ideal for backstabbing) and a revolver.
The Spy is directly associated with several tracks of Team Fortress 2: "Right Behind You", "Petite Chou-Fleur", and "Seduce Me!". The track "A Little Heart to Heart" though not specific to the character, is also often associated with him because of the accordions (a traditional French instrument).
Unlike most of his colleagues like the Heavy, the Demoman, or the Soldier, the Spy never appeared in any rip prior to his formal introduction (minus his appearance on the thumbnail of the Team Fortress 2 playlist, though it is a RED Spy and might be a different character).
In The SiIvaGunner Christmas Comeback Crisis Edit
The Spy first appeared in the rip "Dodo's Coming!! - Super Mario RPG" (although its placement in the lore's timeline is unclear). He infiltrated Soulja Boy's place and found several gold statue of Soulja Boy himself. Unfortunately for him, Soulja Boy sent Loud Nigra check on the statues at the same moment and he had to disguise as one of them to avoid being caught. After "subtly" avoiding Loud Nigra's verification, he still had to let go of the disguise and was unceremoniously shot by Nigra. He however survived the shot thanks to his Dead Ringer and escaped unnoticed.
In the rip "Item_open_crate.wav - Team Fortress 2", we can see the Spy receiving Green de la Bean as a gift from the Voice. (It is subtle, but one can tell it is the Spy's account because he possesses all the Halloween Masks expect for the Spy's one).