Additions:
Researchers: Using an antidote, can turn an infected human back into human again and who can no longer be infected. Using an antidote on a Susceptible or normal Human has no effect.
This could help the game last longer.
The Thing: Special ability: Can make 2 attacks per night if it is the only Alien Creature left which is why there will be 2 attacks on the very first night.
The Thing and Alien Creature can be and is used interchangeably.