Looker was with his Croagunk at the police department in Sinnoh region, as he came to investigate the space and time distortions in the region.
Once Looker recovered from the attack on Stark Mountain, he went to Sunyshore City with Croagunk, and the two arrested Charon for his crimes.
Lou-karr sent Croagunk to battle Black's Tula. The audience, including Black, didn't recognize the Pokémon, as it was not native to the Unova region. Since Black had no information on Croagunk, it attacked Tula, dealing strikes on it. To protect itself, Tula fired Electroweb around itself to prevent Croagunk for reaching it, then fired Signal Beam. However, Croagunk took very little damage from that attack, who retaliated with Vacuum Wave to blow away the Electoweb. Moreover, Croagunk used Poison Sting to pin Tula to the ground and poison it. Tula was badly wounded from Croagunk's punches, but to turn the situation around, it emitted a string to pull the Electroweb that Croagunk blew away with Vacuum Wave. Croagunk was electrocuted and went backwards, crashing into Lou-karr and electrocuting him, too. As everyone cheered for Black, Lou-karr and Croagunk slipped away: Looker took off his disguise and put a policeman hat on Croagunk, to start their investigation as Interpol agents.
Croagunk showed Looker an article about Grey, whom Looker suspected him to be a Team Plasma sage. However, Looker found nothing of the ordinary, except that Grey represented the color between black and white. Looker and Croagunk were in the air ducts, following White, who was speaking with Marlon. When Marlon mentioned the possibility that the Hood Man entered the League illegally, White screamed, which made Looker nearly flinch, to which Croagunk shut his mouth. Looker and Croagunk observed as Black awakened Reshiram. Disguised as Lou-karr, Looker went with Cedric and Leo to help Black. Lou-karr sent Croagunk, who, along with Cedric's Samurott and Leo's Deino, attacked Zekrom. However, the latter was too tough, and blew the trainers' Pokémon away.
Looker paddled a boat with his Croagunk, due to the reports that Team Plasma was regrouping. They went to Aspertia City to meet up with their new superintendent. Their superintendent, Blake, took them to a secret hideout, run by a magician - Blake's manager, where Looker and Croagunk practiced by shooting targets. Croagunk successfully hit the targets with Venoshock, to which Blake praised it and Looker. However, when Dewott turned a button to summon a sandstorm, Looker and Croagunk had a bad performance, and Blake repriminded them. The group suddenly went outside, where they saw a strange Pokémon flying. The Pokémon was Genesect, who was controlled by Colress to attack Blake, Dewott, Looker and Croagunk. Croagunk and Looker observed as Blake captured Genesect. As Looker failed to capture Colress, the latter retreated.
Looker and Croagunk noticed Blake going to the bus with the rest of the school, and Looker reminded himself that a 12-year-old girl should have the chip that could stop Team Plasma. The two also observed Blake combating Tornadus, who was manipulated by Team Plasma. Looker and Croagunk continued observing the battle, and the former realized he had to keep an eye on Whitney, who was with Blake, as she was the girl, suspected to have the chip. Croagunk and Looker paddled the boat, as they followed Blake and the rest of the school to Castelia City, where it was reported that Team Plasma was lurking about.
In the sewers, where Blake, Whitley and Hugh combated Team Plasma, Croagunk was sent to confront Hugh. Through the speaker that Croagunk had equipped, Looker asked Hugh did he knew anything about Team Plasma. Hugh, however, became shocked, as he assumed that Croagunk had the ability to talk. Looker was contacted by Blake, his superintendent, and spoke to him. The voice was transmitted through Croagunk's microphone, which made Hugh wonder if Croagunk's boss was a Toxicroak. Looker nevertheless demanded Hugh to answer his question about Team Plasma. Hugh, however, left, as he refused to say anything to "Officer Croagunk". Croagunk regrouped with Looker, who noticed Blake riding Genesect. It surprised Looker, since Blake wanted to take Genesect to Interpol.
As Blake went missing, Looker and Croagunk went back to Aspertia City. They met up with the magician, who explained that Blake was no longer their superintendent, as he had been fired from the Interpol. Croagunk accompanied Looker to the construction site of the Pokémon World Tournament. However, the two were running away when Skyla wanted to land her airplane near them. Looker and Croagunk fell onto the Plasma Frigate, where they joined Alder. The two also encountered N and Whitley, before confronting Ghetsis. At that point, Kyurem fired an icy blast to hit the Plasma Frigate, an attack that Looker and Croagunk survived.
- ^ D&P078: Double Trouble with Dialga and Palkia V
- ^ PT025: The Final Dimensional Duel XI
- ^ B&W055: The Shadow Triad
- ^ B&W056: One Way or Another
- ^ B&W057: Something Suspicious
- ^ B&W060: Cold Hard Truth
- ^ B&W061: The Power of Dreams
- ^ B2W2001: The Transfer Student
- ^ B2W2002: Mr. Perfect
- ^ B2W2003: Flying Type
- ^ B2W2004: Innocent Scientist
- ^ B2W2006: Movie Panic
- ^ B2W2008: Legendary Tornadus
- ^ B2W2009: New Sword Player
- ^ B2W2010: Choir Tournament
- ^ B2W2011: Angry Boy
- ^ B2W2012: Cold Storage Battle
- ^ B2W2013: Colress Machine
- ^ B2W2017
- ^ B2W2021
- ^ B2W2024