We all make a whoopsie sometime.
RD/KP10-JP060 かっぱの川流し Kappa no Nawanagashi (Kappa’s Unexpected River Ride Blunder)
Normal Trap Card
[REQUIREMENT] When your opponent’s monster declares an attack, you can activate this by shuffling 2 Aqua monsters in your GY back into the Deck.
[EFFECT] The attacking monster loses 800 ATK until the end of the turn. Then, you can choose 1 face-up Normal Monster your opponent controls, it loses 800 ATK until the end of the turn.
Note: かっぱの川流し is close to an idiom in Japanese referring to “Someone who is an expert at someone makes an unexpected blunder”, with the reference here being a Kappa, usually good swimmers, getting caught and flowing down river.