Slaking debuted in Love, Petalburg Style!, where it was staying in Norman's greenhouse with the rest of his Pokémon. It slept throughout the majority of the episode.
Later, when Team Rocket destroyed a fireworks machine that Norman was keeping for his wedding anniversary, he flew into a rage and thus summoned Slaking from inside the greenhouse. On Norman's command, it charged at the terrified trio and violently sent them blasting off with a powerful Focus Punch.
Norman later used it in his Gymbattle against Ash in Balance of Power, where it demonstrated itself as a powerful fighter. With its brute strength, it almost defeated Ash's Grovyle. However, when Grovyle's OvergrowAbility activated, it managed to gain the upper hand and Slaking was defeated.
Unlike most Slaking, this Slaking appears to be very lively and active. This was shown when Norman called it over in order to send Team Rocket flying and during the Gym battle against Ash's Grovyle.
Like in the anime, Slaking is Norman's main Pokémon in the games as well. In Ruby, Sapphire, Omega Ruby, and Alpha Sapphire, as well as the Emerald rematches, he uses two Slaking per battle.
Slaking first appeared in Brushing Past Breloom, where Norman sent him out when he sensed someone's presence. He then had Slaking use Swagger to confuse the hiding individual and reveal them, but the person he had sensed, Ruby, managed to protect himself with Kiki's Safeguard.
In Hanging Around With Slaking I, Slaking was used to battle Ruby at the Weather Institute, easily overpowering Nana and Kiki. After being attacked from Mumu's Mud Shot, Norman had Slaking power up with Bulk Up and then rip out the stairs Ruby was standing in, holding them over an edge and keeping them stable while he talked to Ruby.
In Rayquaza Redemption I, Slaking was used alongside Spinda to help train Wally at the Sky Pillar, facing against Wally's Kecleon and Flygon. While Slaking was hampered by Truant, Wally had Kecleon use Astonish on Slaking while Flygon attacked with Sand Tomb. As a response, Norman had Spinda use Skill Swap to free Slaking from its Truant, allowing Norman to then defeat Wally with a combination of Slaking's Blizzard and Spinda's Teeter Dance.
