The Pyro Update Title update for Team Fortress 2 has 38 achievements.
Kill 3 enemies in a row, all within the same area.
Use your shotgun to finish off 20 players you've ignited.
Have 2 enemy Scouts on fire at the same time.
Force 10 burning enemies to jump into water.
Kill 15 players while you're dead.
Ignite 5 Spies who have a sapper on a friendly building.
Ignite 5 enemies carrying your intelligence.
Ignite 10 cloaked Spies.
Ignite 10 enemies that have recently used a teleporter.
Kill 3 people with your axe in one life.
Kill 6 people with your axe in one life.
Ignite 10 disguised Spies.
Ignite 10 Snipers while they are zoomed in.
Ignite 3 Medics that are ready to deploy an ÜberCharge.
Kill 50 Heavies with your flamethrower.
Kill 10 enemies while you're both underwater.
Kill 3 enemies in a single ÜberCharge.
Destroy 50 Engineer buildings.
Ignite 50 enemies capturing one of your control points.
Kill 500 enemies.
Do 1 million points of total fire damage.
Kill an enemy with a taunt.
Ignite an enemy Spy while he's flicking a cigarette.
Cause a dominated player to leave the server.
Kill 3 enemies while they're taunting.
Ignite a rocket-jumping Soldier while he's in midair.
Provide enemies with freezecam shots of each of your taunts.
Ignite an enemy, and the Medic healing him.
Kill 50 enemies with your flamethrower, from behind.
Kill a burning enemy who was ignited by another Pyro.
Kill a Soldier with a reflected critical rocket.
Kill 1000 enemies.
Ignite 100 enemies with the flare gun.
Reflect 100 projectiles with your compressed air blast.
Kill an enemy in the same second that he kills you.
Achieve 10 of the achievements in the Pyro pack.
Achieve 16 of the achievements in the Pyro pack.
Achieve 22 of the achievements in the Pyro pack.