The fifth gym leader in Pokemon gold is Chuck, who resides in Cianwood City. To get to Cianwood you need the HM surf, which is found in Ecruteak City. You need the fourth badge to use this HM.
Koga. He is a ninja leader. Poison type. In Fushia City. To get to him you have to get through the path of invisible walls. Wouldn't you think a Psychic leader would have that?
~Wariolink
The sixith gym leader in fire red version is Sabrina. She has all physic Pokemon except for venmoth.
Erika is the fourth gym leader in Pokemon FireRed. She uses Grass type Pokemon, and her gym is located in Celadon City.
It is a poison types and the leader is Koga's daugther.
The 6th gym leader in Pokemon Silver is Chuck who uses Fighting-type Pokemon.
Byron in Canalave City
sabirna
beat erika, fourth (celadon) gym leader, who uses grass Pokemon
Veridian city
In Gold the fourth gym Leader is Morty. Morty specializes in Ghost type pokemon, and his gym is located in Ecruteak city.
Koga, he is in fuschia city, he uses poison Pokemon
In cerulean cities gym you must beat the leader misty to get the cascade badge.
Her name is Erika
beat erika, fourth (celadon) gym leader, who uses grass Pokemon
The fifth Gym Leader in Pokemon LeafGreen is Koga, the leader of Fuschia City's Gym. He specializes in Poison-type Pokemon and hands out the Soul Badge.
The 8th gym leader is in Viridian City.
In Celadon city.Celadon City, Leader: Erika. Specialty: Grass. Prize: Rainbow badge.
The fourth gym leader is Erika, the Grass trainer.
The fourth gym at Pokemon fire red is grass type gym
The fourth gym leader is Flannery.
Step on the portals until you get to the gym leader.
Viridian City, Giovanni(Team Rocket Leader) is the Gym leader.
Veridian city
On cinnibar island.