Babe

Seiyu: Masaya Takatsuka Mr. 4 is partner of Miss Merry Christmas. He and his partner are actually, in terms of physical power, stronger than the Mr. 3 Team, but are a lower rank because Mr. 3 is much smarter.

He has a dog called Lasso, which was originally a gun, but "ate" (or rather, merged with) the Inu Inu no Mi, Model Dachshund, a Devil Fruit (イヌイヌの実 モデル ダックスフンド Inu Inu no Mi Moderu Dakkusufundo, called the "Mutt Mutt Fruit in the English anime) and became a gun-dog, who shoots exploding baseballs whenever he sneezes. Mr. 4 then takes out his 4 ton baseball bat and hits the balls at his enemies.

Mr. 4 is rather tall, fat and very strong, but extremely slow in nature, so without Miss Merry Christmas handling the "intelligence", he would not succeed. He is also the only officer agent who doesn't have a Devil Fruit ability (except for Miss Goldenweek whose power might not actually come froma a Devil Fruit). In his team, only Miss Merry Christmas and Lasso have them.

He, Lasso, and Miss Merry Christmas take on Usopp and Tony Tony Chopper during the Straw Hat Pirates' final fights with the Baroque Works during the Alabasta arc, and he manages to severely injure Usopp using a combined attack with Miss Merry Christmas. But Usopp tricks him into knocking out his partner, and then, then using Chopper's horns as a slingshot, defeats Mr. 4 by shooting an extremely fast hammer at him (the move called UsoCho Hamma Suisei or UsoCho Hammer Comet) and knocking him (and Lasso) into a stone structure. Afterward both Mr. 4 and Merry Christmas appear to be finished off by one of Lasso's exploding baseballs. However, all three later seen alive, but in prison, in Miss Goldenweek's chapter title page story. They manage to escape and are now working in the new Spiders Cafe.

Trivia

 * Miss Goldenweek's Rainbow Colour Trap reveals that his dream was to become a pizza delivery boy ("Pizza within 30 hours" as his apron says).
 * Mr. 4's baseball theme is reference to a baseball strategy where you have your best hitter as the 4th batter in the batting line-up. If the first 3 batters manage to get a base each, the 4th player then has a chance to get the best points for the team.
 * The Mr.4 pair is given a clear "physical strength" theme, which should not be needed to explain.