The Thing gamemode

It would be awesome, it would function like the game and the movie, one player starts infected and after a while they become a Thing, The thing team would have a tier based system where you unlock new classes through kills.

Classes:

Humans:

Soldier
Engineer
Medic

Things:

Tier 1:

Crawler:

Infector? (Dog Thing):

http://www.best-horror-movies.com/image-files/the-thing-dog-monster.jpg

Weapons:

Flamethrower. (Kills T2 to 4 without allowing them to regenerate.)
MG. (Kills T1 and weakens higher tiers.)
Rockets. (Starts fires. Kills T5.)
Grenades. (Same as rockets but wont kill T5.)
Pistol. (See MG.)

Players:
Atleast TEN. (Or make NPCS of the infected.)

Ill update it more in a minute.