This sound comes from Scout, the fast-talking character in Valve's Team Fortress 2, released in 2007. Short Scout voice lines like this spread widely through gameplay videos, frag compilations, and meme edits because they are punchy and easy to recognize. The word 'bonk' also fits visual comedy on its own, so the clip stayed popular beyond the game community. It is still used as a quick impact joke in gaming posts, reaction edits, and cartoonish fail moments.