Sperm is a character in the game, You Have To Fertilize the Egg. The Sperm is the protagonist in the game. The Sperm is a sperm cell that wears a top hat. The Sperm cell also sings the lyrics "I'm swimming around in a vagina, I tried to make a princess". PewDiePie sings along with the sperm cell in the game. The sperm cell was seen in Pewdie's commentary of the game, as a bonus upload, on January 24, 2012.