Mr. 4

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. He is the only male officer agent other then mr. 5 to be working at the Spiders cafe.
 Abilities and Powers

He is one of two officer agents without a Devil Fruit ability, the other being Miss Goldenweek. He is very strong, but extremely slow in nature, so without Miss Merry Christmas handling the "intelligence", he would not succeed. 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.

Techniques:

Yonhyabban Punk Knock (400 Punk Knock): This attack's not officially named by him, but by his partner Miss Merry Christmas. He has Lasso shoot a huge group of his exploding baseballs then Mr. 4 hits half of them back at a surprisingly swift speed into the cluster detonating them all at once and creating a massive explosion.

Mogurazuka Yonban Kousaten (Molehill Intersection Number 4): A combo attack with Miss Merry Christmas, first Miss Merry Christmas uses her Mogurazuka Highway technique and carries the opponent past Mr. 4 who, upon hearing her call out the attack, smacks the captive with his 4-ton bat causing massive damage to anyone unlucky enough to be the victim of this attack, though he may accidentally hit an ally as he is too dim witted to note differences in the voice.
Personality

Mr.4 was the slow and dimwitted partner of Miss Merry Christmas. He seems incapable of thinking for himself at all and often just does as his partner tells him to do. He laughs freely, but speaks rarely- in contrast to his partner, he speaks very slowly, usually taking most of a scene to articulate a short sentence.