Gage Briody is a pre-made townie living in Sunset Valley who can be seen wandering around town. He can be made playable by marrying him, or asking him to move in.
If story progression is turned on, Gage will often move to a random house once the population decreases. He does not have any skills learned at the start of the game.
He also has a double who is exactly like him, he can be found in CAS saved sims. All of his facial characteristics have sliders set to neutral. This occurs with all other Sims randomly generated by the game as well. This is nicknamed "pudding face."