The title refers to The Meg, the 2018 action film about a giant megalodon shark resurfacing from the deep ocean. Short reaction sounds named after films like this circulate on soundboards as reusable shorthand for shock, rather than as official clips from the movie itself. Editors borrow the label to signal an instant, exaggerated response to scale and danger. It stays popular because huge reveals, jump cuts and creature features remain common in meme edits, and a two-second reaction fits almost any oversized surprise built on sudden suspense.