"My name is Morty. I am Ecruteak's Gym Leader. Because my old friend is here on the trail of Suicune, I decided to investigate the Burned Tower. Ecruteak has a legend about these legendary Pokémon: Suicune, Entei, and Raikou. As the Gym Leader of Ecruteak, I must have a proper understanding of it."
He appeares in JE065: A Ghost of a Chance, JE066: From Ghost to Ghost, and EP227. During this time, he fought against Ash in a gym battle. Also, when Ash returned to Ecruteak City, he saw Morty again, and Morty is worried about the Burned Tower near Ecruteak City.
In the games
Morty, first appeared in the Generation II games as the Ecruteak CityGym Leader, specializing in Ghost Pokémon. His Gym holds a large, pitch black, pit where the the player must navigate their way on a small invisible walkway in order to reach him. Upon defeating Morty, he will reward the player with TM30 (Shadow Ball), and the Fog Badge.
Morty's name may be a play on the word MORTUARY, which is a funeral home, because he is a ghost type trainer. Similarly, it could come from the Latin adjective meaning 'dead', mortuus.