Morty's Gengar was first seen in the Burned Tower, creating an illusion with other Haunter and Gastly to deceive
Ash Ketchum and the rest of the group into thinking that the tower was aflame and burning to the ground.
Morty notes that many challengers believe that the Burned Tower is actually the Ecruteak City Gym, so the Ghost-type Pokémon attempt to ward off the trespassers by creating illusions. Later on, Morty's Gengar battled and defeated
Jessie's Arbok and
James's Weezing, retrieving
Ash's Pikachu and
Misty's Togepi for
Ash Ketchum and
Misty, respectively.
Before the Ecruteak City Gym Battle against
Ash Ketchum , Gengar was seen helping
Morty demonstrate the deceptive powers of Ghost-type Pokémon to the students of the gym by using Confuse Ray on a group of Gastly. Gengar was the third and final Pokémon used by
Morty in the gym battle, facing off against
Ash's Noctowl.
Ash's Noctowl started the match with a Confusion attack, but Gengar countered using Shadow Ball. Gengar's invisibility made it difficult for
Ash's Noctowl to use Foresight, so
Ash's Noctowl used a wide-range Confusion attack to stun Gengar. Then,
Ash's Noctowl was able to use Foresight and expose Gengar. Gengar attempted to counter with a Shadow Ball, but
Ash's Noctowl was too quick and hit with a Tackle attack for the victory, defeating Gengar and giving victory in the Ecruteak City Gym Battle to
Ash Ketchum.