Final answer:
In real-life Quidditch, a tennis ball in a sock is used to simulate the golden snitch, with a player called the 'Snitch Runner' wearing it during the game.
Step-by-step explanation:
In real-life Quidditch, which is adapted from the Harry Potter series, a tennis ball in a sock is used to replace the magical golden snitch. This adaptation is part of Muggle Quidditch, a game that seeks to translate the magical sport into a real-world equivalent. A player called the 'Snitch Runner' has the sock with the tennis ball attached to the back of their shorts, and seekers from each team attempt to grab it to score points for their team and end the game.