O.V.E.R.P.O.W.E.R.E.D. B.L.I.M.P.

The O.V.E.R.P.O.W.E.R.E.D. B.L.I.M.P. (short for Overpowered, Very Evil, Robotic Plague Of Weirdly Effective, Resistant, Extremely Destructive, Balance-Lacking, Insurmountably Maximized Power) is a blimp that can come randomly at any time. It cannot be damaged by anything. As soon as it is fully on the screen, it breaks up into a swarm of Nano-Bloons, which cannot be damaged by anything either. The Nano-Bloons then move to each tower, special agent, or item that you have placed on the track in turn, surrounding them and then blasting them with a superpowered beam that is impossible to avoid, causing them to be utterly destroyed. After destroying everything, the Nano-Bloons fly toward the camera and shoot their beam at it. The game then blacks out, forcing you to refresh the page if you want to play more.