Alien Swarm Parasite
The Alien Swarm Parasite is a promotional headwear item for all classes. It is a stylized version of an enemy parasite from the game Alien Swarm. The creature attaches to each class's head differently, and sports a limp tail.
The Alien Swarm Parasite is obtained by earning the Hat Trick achievement in Alien Swarm. The achievement is earned by completing two co-op missions online, regardless of difficulty setting.
| Hat Trick|
Complete 2 cooperative missions online. Earns a Team Fortress 2 parasite hat.
- Alien Swarm Parasite was added to the game.
- Fixed this hat not being posed correctly on class loadout panels.
- [Undocumented] Added a community-contributed description for this hat.
- This hat was made paintable.
- [Undocumented] Brain Parasites are now credited as being assisted by the player on unassisted kills.
- The hat description was written by Grug for the Hat Describing Contest, but was slightly edited by Valve.
- If the parasite is shot after falling off its owner's head, it will bleed.
- Additionally, if the parasite is propelled across the floor, it will leave a trail of blood.