The 'Hol' Up' meme features a modified version of the iconic Vault Boy mascot from the Fallout video game series, specifically depicting him with a skeptical, squinting expression. It gained massive traction on Reddit, particularly within the r/holup subreddit, which focuses on content that starts off normal but concludes with a jarring or unexpected twist. The meme is used as a reaction image to flag statements that are subtly dark, illegal, or socially unacceptable upon second glance. It perfectly encapsulates the feeling of a 'double take' when someone realizes a situation isn't as innocent as it first appeared.