Taunts

From TF2 Wiki

Each class has its own series of taunts. These can be performed at any time (Default key: G for PC, "X" for Xbox 360 and "Square" for PS3), with each class having a separate taunt animation for each weapon. Each taunt has several lines of dialog that are chosen at semi-random (one taunt is chosen at random and every taunt after it follows a specific list). Taunts are generally used to challenge or insult a player on the enemy team. Exercise caution when taunting. You are vulnerable while performing a taunt as your view will shift to third-person and you will be unable to act until the taunt is concluded. Some weapons do not have taunts, such as the Electro sapper. Only 2 taunts cause damage so far, the Pyro's Hadouken and the Heavy's Showdown, which will cause 450+ damage on a successful hit.

Taunts can also be glitched to produce cool tricks. A popular one is to taunt, then immediately switch to another weapon (usually through the 'use previous weapon' key), so that you taunt with a different weapon. In addition, pressing jump immediately after pressing the taunt button will allow you to move while the taunt is occurring. (360 and PS3 versions only, this has been fixed in the PC version)

Another such trick is to cancel the taunt - this is accomplished by forcibly moving the player in mid-taunt. Compression blasts work nicely, but the player can do this himself by simply taunting close enough to an edge while moving such that he slides off of it. If the player is successful in sliding off of the edge, he will be returned to firstperson and be able to fire weapons and move normally, but to other players he appears to continue the taunt animation. An example of this is a demoman taunting with the grenade launcher off of a ledge, then firing - it will appear that the grenades launch from his crotch as he shouts "ka-boom".

The Heavy's unlockable Sandvich when used with either mouse1 or the taunt key is both an ability and a taunt, moving to third person view and rendering the player immobile.

Note that you cannot taunt while underwater.

Removed Taunts

Only one taunt has so far been found to have been removed from Team Fortress 2. It is a secondary taunt for the Medic class.

Called, 'Taunt06' in the files, it depicts the Medic holding his medigun by the barrel towards his face, bending over it and taking a deep inhaling breath before relaxing.

It has been speculated that this references the smoking of a bong and therefore may have been removed to avoid drug references.