The 'Tuna Sub Backwards' meme is a popular linguistic prank and wordplay joke that relies on the phonetic reversal of the phrase 'Tuna Sub' to reveal the slang expression 'Bus a Nut.' While the origins are rooted in early internet chat rooms and schoolyard humor, the meme saw a resurgence on platforms like TikTok and Twitter as a bait-and-switch gag. It typically features an image of a generic tuna sandwich or a person reacting with sudden realization once they decipher the hidden message. The meme thrives on the 'gotcha' moment, often used to catch unsuspecting users off guard with its crude yet simple phonetic twist.