Sans is the laid-back skeleton from Toby Fox's Undertale, first released in 2015, who became one of gaming's most quoted and remixed characters through fan videos, streams and memes. His calm jokes, hidden strength and infamous boss fight made him a shorthand for a character who seems harmless until the difficulty suddenly spikes. Clips like this one spread in that fan culture, where a short reaction sound can carry the whole joke without needing the full game context, and they remain popular because new players keep discovering Undertale and rediscovering why Sans is so memorable.