Young Buffalo

Means "trẻ trâu", a slang in Vietnam, used to describe different types of people that are usually toxic, edgy, stupid,... blahblah.
The word "trẻ" (Subject) does not mean "young" (Adj), It means "kid" and "trâu" means "buffalo". It can be easily understood as a stupid heady kid.
This word does not have an exact meaning now. No one knows where did it come from.
Bonus: You can meet these lil dudes in Vietnam's League server.

(Usually a Yasuo player, playing Yasuo does not make you a young buffalo, but every young buffalo likes to play Yasuo)

*In a normal Vietnam's League match...
Yasuo: "My job here is done." (0/11/3)
Lux: "But you did nothing" (4/5/3)
*Yasuo has disconnected from the game
Lux: "What a f**cking young buffalo!"