The phrase combines sus, slang from the game Among Us that shortened suspicious, with baka, the Japanese word for fool or idiot. Sussy baka spread widely on TikTok and YouTube in 2021 as a playful insult used in voiceovers, anime edits and gaming clips. People would say it in a silly voice to accuse friends or characters of acting strange without being serious. Its mix of gaming slang and anime language helped it stick as a lasting meme sound for reactions and jokes online.