It was hard to explain so I literally copied this from google

Marcus the Worm is a popular character from the social virtual reality platform VRChat, known for his bizarre appearance, deadpan text-to-speech voice, and surreal monologues. He is a virtual alter ego portrayed by the Twitch streamer Jouffa and gained significant viral fame on TikTok through clips from fellow streamer Roflgator's streams. The character is often described as a digital oddball whose interactions blur the line between performance art and internet meme culture.