Hearthstone's death bgm comes from the pure music "Epic Sax Guy". This song will appear every time you watch the fishy moment and be killed by the opponent. In Hearthstone videos, it is often played when OTK kills an opponent, so it is also called "The Divine Song of Killing" by Hearthstone players.

Extended information

"Epic Sax Guy" is a well-known and familiar piece of pure music. Electronic music with saxophone as the main melody. Released on January 1, 2010, it is often used in various online videos. The interlude from the dance song "Run Away" by the group Sunstroke Project is more commonly used in various online videos. SunStroke Project is the name of a band composed of the trio Sergei Yalovitsky (vocals), Anton Ragoza (violinist and composer) and Sergey Stepanov.

Reference: Baidu Encyclopedia-Epic Sax Guy