The Surprise Party couch gag is the tenth couch gag of Season 16.
A group of recurring characters run into the living room, which is very dark. When the Simpson family runs into the room, the lights suddenly turn on, and the room is set up with balloons, streamers, and a banner that reads, "SURPRISE!" As the lights go on, the recurring characters all yell, "SURPRISE!" Eventually, Homer becomes suprised and suffers a heart attack before collapsing.