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