From Bulbapedia, the community-driven Pokémon encyclopedia.
B-2 (Japanese: Ｋ－２) is a recurring Galactic Grunt in the Pokémon Diamond and Pearl Adventure! manga. He claims that as a Grunt he "has no name" and is thus called by his assigned number B-2 (a spoonerism of the word "booty"). (K-2 in Japanese, pronounced as ケーツー, a pun on "けつ", the Japanese word for "butt".)
B-2 after his buttocks become swollen
B-2's first appearance was in Hareta's Very First Pokémon Battle!! in Jubilife City with another Grunt. The two of them confront Hareta (who has wandered off while Mitsumi was speaking) and noting the rarity of his Piplup, they demand he hand it over. Hareta refuses, however, and gets angry upon recognizing their smell as being the same one as when Onix went crazy. One of the Grunts commands their Wurmple to use String Shot on Hareta and Piplup so they can snatch Piplup and make a clean getaway. However, Hareta manages to follow the pair to Oreburgh Gate, where he manages to bite B-2's rear before being taken down by the other Grunt's Wurmple's Poison Sting. The pair of Grunts bring Hareta to the Oreburgh Mine, with B-2 stating that they're going to make him regret not only crossing their path, but also biting his buttocks, which are noticeably swollen by now. Before they can exact their revenge, though, they are defeated by Roark who happens to be nearby and the pair subsequently flee.
When B-2 reappears, he is on his own on the road to Celestic Town carrying a briefcase containing a "Secret Item". Hareta asks if he's up to no good again. B-2 refuses to tell him, but then blabs anyway that it's an item to catch a legendary Pokémon that must be kept secret until delivered to his boss. After Mitsumi points out that he just revealed everything, the grunt panics deciding that he must now hurry in order to deliver it. However, as he begins to run, Cynthia trips him. He then sends out his Beautifly to battle, but it is instantly defeated by Piplup. Sending out three Wurmple, he has them all use String Shot together. Hareta appears to be in trouble unable to deal with this amount of string, until Cynthia's Garchomp helps out. However, the String Shot was merely a diversion and B-2 had already escaped.
When Hareta and Mitsumi arrive in Celestic Town, they encounter B-2 and a group of other Galactic Grunts at the Celestic Ruins. He says that they're too late and has already delivered the item to his boss and is now on his next assignment. After Cynthia's grandmother refuses to divulge any information about Dialga, he activates a bomb to destroy the relics. Hareta attempts to disarm the bomb, but instead reduces the time remaining from 5 minutes to 30 seconds. B-2 and the other Grunts then call a hasty retreat.
B-2 and Hareta after considering each other "butties"
The next appearance of B-2 is on Iron Island. Hareta challenges him to a battle and his Graveler is then defeated by Riley's Lucario. As Hareta and Riley train together, they notice that all the wild Pokémon on Iron Island are in a rage. Eventually, B-2 reveals himself to be responsible and attacks with his Drapion. Through a tag-team of Hareta's newly hatched Riolu and Riley's Lucario, B-2 is defeated and flees once again.
He is also present at Lake Valor, where he reveals that the briefcase he delivered to the boss earlier was actually the Galactic Bomb which drained the lake. He tells Hareta that he stands no chance against all the Galactic Grunts gathered there alone; however the Sinnoh Gym Leaders appear to take care of the Grunts while Hareta and Byron deal with Saturn. As the events at Lake Valor unfold, Cyrus himself becomes involved and in the end Team Galactic is defeated, however B-2 still manages to escape with the captive Azelf.
He later appears at the Snowpoint Temple, where he witnesses the battle between Hareta and Regigigas. When he is found after the battle, Byron tells him to go tell Cyrus that the end is near.
When Hareta and the Gym Leaders arrive at Team Galactic HQ, B-2 is the designated watchman. When everyone (other than Byron) decide to have a picnic outside before going in, he asks them what they're doing out here and Hareta tell him that they're having a picnic and asks him if he wants to join. B-2 accepts the invitation. After everyone has eaten their fill, B-2 is swiftly defeated in battle and Hareta and the Gym Leaders storm the building. This culminates with the building's self-destruction as Cyrus escapes to Mt. Coronet with the Red Chain.
When Hareta is on his way to the Spear Pillar to stop Cyrus, after defeating Mars, B-2 steps in binding Hareta with his Wurmple's String Shot. However, as a light shines down from the summit, Mars and the still bound by string Hareta head up to the Spear Pillar, as the grunt calls out for them to wait up. After this, he appears to be the last person to arrive at the summit, being there in time to help with Cyrus's plan to stop Dialga and Palkia and send them back to where they came from.
After this, B-2 is not seen again until much later when Hareta comes to take on Charon at the new Galactic Headquarters in Veilstone. B-2 begs Hareta to help him save Cyrus, to which Hareta, and subsequently Jun and Mitsumi agree to. Before going to the HQ, Hareta asks him if he has a name, at which point he finally introduces himself as B-2. However arriving outside HQ, Koya is there, refusing to let them in as Hansom is currently in there taking care of Team Galactic with a Super Elite Squadron. However, Hansom soon calls alerting Koya that the mission was a failure, prompting him and the others to enter. They find Charon with an army of ferocious Pokémon, deciding to leave it to Hareta and Koya, B-2 asks Mitsumi and Jun to help him save Cyrus in the meantime.
After Cyrus is rescued, B-2 takes Professor Rowan to help Hareta stop Charon and his evil plans. As soon as they arrive, the plane B-2 is piloting is nearly sucked into the massive portal created by Giratina. They manage to escape in time to give their support to Hareta's group.
- Due to his lack of an actual name in earlier volumes, some fans have taken to calling him Uranus as a combined reference to the planetary naming for the Commanders and his swollen buttocks.
- Since B-2's appearance, it has been a gag that every time he appears, something will happen to his buttocks.
- B-2 actually has an attack called "Butt Bump" which he used against Hareta's Piplup in Serious Training on Iron Island!!.