When Team Rocket ran off with Pikachu and Togepi, Gengar appeared and tripped them with Lick. Gengar then gave chase to Team Rocket. After it knocked Pikachu and Togepi out of Team Rocket's grasp, the trio sent out their Arbok and Weezing to battle Gengar. However they were easily defeated by Gengar's powerful Shadow Ball.
In From Ghost to Ghost, Gengar demonstrated to a group of Trainers in the Ecruteak Gym its Confuse Ray attack. During the Gym battle with Ash, Morty sent Gengar out as his last Pokémon. Ash's Noctowl began with Confusion, which Gengar countered with Shadow Ball, which caused an explosion. Gengar used the opportunity to become invisible. Gengar then attacked Noctowl with Night Shade, demonstrating its ability to attack even when invisible. When Ash told Noctowl to use Confusion on the whole building, Gengar was revealed. With Gengar visible again, Noctowl used Foresight to identify Gengar and finished it off with Tackle, defeating Morty and earning Ash the Fog Badge.
Gengar reappeared in a flashback in All That Glitters!, when Ash was recalling the time he received the first four badges of Johto.
Gengar is usually outside of its Poké Ball and hiding in the shadows, though appears when needed. It has mischievous nature and enjoys pranking people, especially those who enter the Burned Tower. Though Gengar has been shown to be helpful especially with cases with Pokémon or items stolen by Team Rocket.It has the ability to become invisible and reappear before its opponent notices. However, Ash overcame this by having his Noctowl use Confusion on the whole gym.
A † shows that the move was used recently, unless all moves fit this case or there are fewer than five known moves.
In the TCG
Morty's Gengar is featured in the TCG as one of Morty's Pokémon. The following is a list of cards named Morty's Gengar.
Morty's Gengar Cards listed with a blue background are only legal to use in the current Expanded format. Cards listed with a silver background are legal to use in both the current Standard and Expanded formats.