Oil Panic (move)
From the Super Mario Wiki
When used, Mr. Game & Watch will pull out a bucket in front of him and can absorb any energy-based projectiles (such as PK Flash or a Ray Gun shot) into the bucket. If this move is used after three attacks are absorbed, Mr. Game & Watch will throw out the oil in his bucket which has extreme damage and knockback, determined by adding up how much damage each of the projectiles absorbed would have done. The oil splash can also be enough to one-hit KO if it has absorbed three projectiles that are strong.
One custom variant that appears in Super Smash Bros. for Nintendo 3DS / Wii U is Efficient Panic, where the bucket only requires one projectile, but the splash deals less damage. Another variant is Panic Overload, with the bucket having a smaller absorption range, but the splash is larger.