The phrase combines two familiar pieces of internet anime slang, with baka used as a lighthearted insult in fan edits and dubbed clips, while smelly adds a childish, schoolyard sting. It circulates mainly as a short reaction sound on meme pages and soundboards, where its brevity makes it easy to reuse across gaming clips, anime edits and everyday roasts. Its staying power comes from that simple formula: a recognisable anime-style insult that is silly enough to stay friendly, even when it is aimed at a friend.