Da blin, kapets is a piece of everyday Russian internet slang rather than a line from a known film or show, so its exact original recording is not widely documented. The phrase combines a mild swear word for damn with kapets, slang for a disaster or something totally over the top, making it a compact way to say this is unbelievable. Russian-speaking creators adopted it as a quick reaction sound for short videos, streams and meme edits, where its raw, unpolished delivery carries the joke even for viewers who only catch the tone.