Spy

"This Spy has already breached our defenses... You've seen what he's done to our colleagues! And worst of all:

He could be any one of us."

- The BLU Spy on the Red Spy

The Spy, hailing from an indeterminate region of France, is a fan of sharp suits and even sharper knives who relies on stealth and trickery to aid the team. Using his unique array of cloaking watches, he can render himself invisible or even fake his own death, leaving unaware opponents off-guard. His Disguise Kit lets him take on the form of any class on either side, allowing him to blend in while behind enemy lines before literally stabbing his unsuspecting 'teammates' in the back. In fact, a swift backstab with any of the Spy's knives will take out any foe in a single hit.

In addition to being able to assassinate key enemies quickly and efficiently, the Spy has advantages over the Engineer. Using his Sappers, he can disable the Engineer's buildings – slowly draining their health until they are destroyed unless removed by an Engineer or a Pyro wielding the Homewrecker or Maul. He can also make use of enemy teleporters to surprise (and maybe even telefrag) his foes.

Two other common Spy targets are the Heavy and the Medic. While a Heavy has one of his spun up, he moves at a far slower speed than normal – this slower move speed along with the distraction of combat makes for an easy opportunity for a backstab. Medics must focus on their healing target, which also leaves them vulnerable to backstabs. Snipers are also obvious Spy targets due to their slower movement speed and lack of nearby awareness when scoped into their Sniper Rifles. Snipers can use a Razorback to defend themselves from a single backstab, which also stuns the offending Spy. Whereas most players can only see the names and health of teammates, the Spy can observe the names and healths of the enemy team as well, allowing him to relay useful intelligence. Only a Medic carrying the Solemn Vow shares this ability. The Spy is voiced by Dennis Bateman.

Role in Moments with Heavy
While he's only been seen once on the show in person (also mentioned by the Medic), he does seem to be sort of an antagonist, as he was seen laughing at an Uber-Charged Heavy, and was then punched into an abyss for doing so. (He was then hospitalized afterward with a neck chain.)