Wu Ke tells a video for Ge Ping, the voice actor of Blue Cat. According to Ge Ping, Wu Ke is a child with a shaved head, because the tone used in Ge Ping's video is too happy. After it was widely spread, netizens used Wu Ke to refer to the role of bald head.

BGM refers to music as the background, which is often used to render the atmosphere.

Bring your own BGM means that every time a character appears, BGM will switch to the music exclusive to the character, or the music conforming to the character temperament, or other specific music. It is often used to describe a person who has a strong aura, or to express that this person is a typical person. (The more "correct" explanation is that BGM does not change with the appearance of characters, but the characters bring their own equipment to play BGM. )

Wu Ke's BGM probably comes from the crazy father of RPG horror game, which has a mysterious bald demon character. As an important supporting role and clue of the game, BGM suddenly changes every time it appears, and is described by players as a man with BGM.