"Why don't you guys grab a glass of water while we wait."The Agent, Airplane 2
The Agent is first seen when he is seen finishing up a conversation, saying a suspicious line, "And remember, no one should know about this!". The agent warns the player not to provoke the President, and that he gets mad easily. While the players and the agent wait for the President, the agent offers the players a glass of water. When a player clicks on the glasses it will spill everywhere, and the players must clean it up in time, or the Agent will lock the spiller away for the rest of the flight.
Next when the President chooses a random player to cook a meal, the Agent instructs the players how to drop items in the soup, and then shouts out the ingredients for the player. Finally the Agent accompanies the players to the Computer Room, which he says protects them from any cybernetic attacks to the systems. The players must then work in a code before they can get into the President's Office. After the Computer Room the Agent is not seen again until the Endgame.
Then, he is seen accompanying the President in the Endgame. If the President is shot, the Agent will reveal himself as the Monster and kill everybody on the plane. If the Agent is shot instead, the unmasked Monster will appear on the floor, presumably dead. If the player chooses not to shoot, then the Agent will arrest all the players for attempting to assassinate the President.
The Agent's personality is largely unknown, but it is implied he is serious and he has a strong work ethic, as given by their relatively monotone speech.
Additionally, he appears to be a backstabber, having allowed the Monster onto the plane and helped him initiate his plan.