Ecruteak City Gym is the gym of Ecruteak City. Morty is the gym leader which has Ghost-type Pokémon. If the player wins against Morty he/she gets the Fog Badge and TM30 Shadow Ball. The player can also use Surf out of battle and Pokémon up to level 50 obey the player.
In Generation II the Ecruteak Gym which has invisible floors can cause problems because a simple touch to the invisible pit makes the player become sent back to the start of the gym and start the process over again. Trainers appear as if they are floating over the floor and sometimes are scared away by Gastly.
While in Generation IV, the Ecruteak Gym has slightly changed. The change is about there are some flames that light up dark patches. It's harder for the player to see where he/she is going because if he/she defeats each Medium, their flames go out when they lose. And there are no Sages in the Gym.
In Pokémon Stadium 2 The Gym was like an eerie temple or ritual site with a glowing floor.