GLaDOS is the artificial intelligence at the centre of Valve's Portal puzzle games, first released in 2007 and voiced by Ellen McLain. Her dry, robotic delivery and dark humour made her one of gaming's most recognisable characters, and short lines like this one are widely shared as reaction clips. Gamers use the warning in Portal playthroughs, speedruns and edited montages, and it has spread beyond the games into memes about unexpected enemies, difficult levels and friends turning against the player.