"Vestigial Peter" is the second episode of the twelfth season and the 212th overall episode of the animated comedy series Family Guy. It aired on Fox in the United States and Canada on October 6, 2013, and is written by Brian Scully and directed by Julius Wu. In the episode, Peter finds a strange lump on his neck that turns out to be a vestigial twin, who ends up winning over Peter's family and friends with his optimism and sense of wonder.