Dee Dee is Dexter's older sister in Dexter's Laboratory, the Cartoon Network series that premiered in 1996 and became a staple of 1990s cartoon comedy. Known for her curiosity, ballet dancing and habit of barging into her brother's secret lab, Dee Dee often turned his inventions into chaos, and her bright laugh became part of that playful disruption. Clips of the laugh later circulated as a reaction sound in memes and short videos, where it signals innocent mischief rather than cruelty. Its short length and instantly recognisable cartoon tone keep it useful for creators today.