Prior to his introduction, Colress used Beheeyem in multiple plots to advance Team Plasma's goals, such as manipulating weak-minded people into releasing their Pokémon so that more people would be influenced to do the same and erasing the memories of the Gym Leaders during their kidnapping.
Beheeyem first appeared in The Tournament Continues, where he was used by Colress in the quarter-finals of the Pokémon League, going up against Marlon's Jellicent. Jellicent started with a strong Scald, which burned Beheeyem in the process. Colress was unfazed, however, and had Beheeyem restore his health with Recover, boost his stats with Calm Mind, and score a direct hit with Energy Ball. Jellicent Recovered as well, and rushed forward to grab Beheeyem with his tentacles. Unable to use Energy Ball again because of Cursed Body, Beheeyem fired off a Shadow Ball from his shadow, defeating Jellicent and advancing Colress to the next round.
In Something Suspicious, Beheeyem was used in Colress's semifinal battle against Cheren and his Unfezant. Beheeyem repeated the strategy of using Calm Mind before attacking with Energy Ball, but Unfezant was able to dodge the move and defeat Beheeyem with a single U-turn.
When White attempted to rat Colress out in True Friends, Beheeyem Teleported her and Colress out of the stadium.
In A Difficult Parting, Colress sent Beheeyem to aid Ghetsis. Using his psychic powers, he freed Ghetsis from his prison, threw Black into the Light Stone, and Teleported Ghetsis to safety.
In Innocent Scientist, Beheeyem once again Teleported Colress to safety, this time after his defeat to Blake.
In Angry Boy, Beheeyem used Wonder Room to help Colress interrogate Zinzolin. Once Zinzolin revealed Kyurem, Beheeyem stayed to the sidelines, only attacking when Zinzolin tried to pick up the Colress Machine.
In PS548, Colress gave Beheeyem a new version of the Colress Machine to protect, sending him instructions through a microphone. Blake figured this out and sent his team after Beheeyem, though it was able to evade them until Blake's Kelden showed up. The new Colress Machine was destroyed, but it was revealed that it was merely a distraction.