Union Cave: 23 species in 3 games

Gold and Silver Crystal HeartGold and SoulSilver

Area 1 of 3

Union Cave (1F): 14 species across 5 versions

Gold: 10 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	4	10%	All places
Sandshrew	Walking in tall grass or a cave	6	30%	All places
Zubat	Walking in tall grass or a cave	5 to 7	25%	All places
Geodude	Walking in tall grass or a cave	6	30%	All places
Onix	Walking in tall grass or a cave	6	5%	All places
Goldeen	Fishing with a good rod	20	65%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	15 to 19	60%	All places
Quagsire	Surfing	15 to 24	40%	All places

Silver: 9 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	4 to 6	40%	All places
Zubat	Walking in tall grass or a cave	5 to 7	25%	All places
Geodude	Walking in tall grass or a cave	6	30%	All places
Onix	Walking in tall grass or a cave	6	5%	All places
Goldeen	Fishing with a good rod	20	65%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	15 to 19	60%	All places
Quagsire	Surfing	15 to 24	40%	All places

Crystal: 10 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	4 to 6	up to 40%	All places
Sandshrew	Walking in tall grass or a cave	6	up to 30%	All places
Zubat	Walking in tall grass or a cave	5 to 7	up to 25%	All places
Geodude	Walking in tall grass or a cave	6	up to 30%	All places
Onix	Walking in tall grass or a cave	6	up to 5%	All places
Goldeen	Fishing with a good rod	20	65%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	15 to 19	60%	All places
Wooper	Walking in tall grass or a cave	5	20%	All places
Quagsire	Surfing	15 to 24	40%	All places

HeartGold: 14 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	4	10%	All places
Sandshrew	Walking in tall grass or a cave	6	up to 20%	All places
Zubat	Walking in tall grass or a cave	5 to 7	up to 20%	All places
Geodude	Walking in tall grass or a cave	6	up to 20%	All places
Onix	Walking in tall grass or a cave	6	5%	All places
Goldeen	Fishing with a good rod	20	60%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	40%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	10 to 20	60%	All places
Quagsire	Surfing	10 to 25	40%	All places
Makuhita	Walking in tall grass or a cave	5	20%	All places
Absol	Walking in tall grass or a cave	6	20%	All places
Chingling	Walking in tall grass or a cave	5	20%	All places
Bronzor	Walking in tall grass or a cave	6	20%	All places

SoulSilver: 13 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	4 to 6	up to 30%	All places
Zubat	Walking in tall grass or a cave	5 to 7	up to 20%	All places
Geodude	Walking in tall grass or a cave	6	up to 20%	All places
Onix	Walking in tall grass or a cave	6	5%	All places
Goldeen	Fishing with a good rod	20	60%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	40%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	10 to 20	60%	All places
Quagsire	Surfing	10 to 25	40%	All places
Makuhita	Walking in tall grass or a cave	5	20%	All places
Absol	Walking in tall grass or a cave	6	20%	All places
Chingling	Walking in tall grass or a cave	5	20%	All places
Bronzor	Walking in tall grass or a cave	6	20%	All places

Area 2 of 3

Union Cave (B1F): 14 species across 5 versions

Gold: 10 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	6	5%	All places
Sandshrew	Walking in tall grass or a cave	8	30%	All places
Zubat	Walking in tall grass or a cave	7 to 9	25%	All places
Geodude	Walking in tall grass or a cave	8	30%	All places
Onix	Walking in tall grass or a cave	8	10%	All places
Goldeen	Fishing with a good rod	20	65%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	15 to 19	60%	All places
Quagsire	Surfing	15 to 24	40%	All places

Silver: 9 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	6 to 8	35%	All places
Zubat	Walking in tall grass or a cave	7 to 9	25%	All places
Geodude	Walking in tall grass or a cave	8	30%	All places
Onix	Walking in tall grass or a cave	8	10%	All places
Goldeen	Fishing with a good rod	20	65%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	15 to 19	60%	All places
Quagsire	Surfing	15 to 24	40%	All places

Crystal: 9 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	6 to 8	up to 10%	All places
Zubat	Walking in tall grass or a cave	6 to 8	up to 50%	All places
Geodude	Walking in tall grass or a cave	8	up to 30%	All places
Onix	Walking in tall grass or a cave	8	up to 10%	All places
Goldeen	Fishing with a good rod	20	65%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	15 to 19	60%	All places
Wooper	Walking in tall grass or a cave	8	20%	All places
Quagsire	Surfing	15 to 24	40%	All places

HeartGold: 14 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	6	5%	All places
Sandshrew	Walking in tall grass or a cave	8	up to 20%	All places
Zubat	Walking in tall grass or a cave	7 to 9	up to 20%	All places
Geodude	Walking in tall grass or a cave	8	up to 20%	All places
Onix	Walking in tall grass or a cave	8	10%	All places
Goldeen	Fishing with a good rod	20	60%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	40%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	10 to 20	60%	All places
Quagsire	Surfing	10 to 25	40%	All places
Makuhita	Walking in tall grass or a cave	7	20%	All places
Absol	Walking in tall grass or a cave	8	20%	All places
Chingling	Walking in tall grass or a cave	7	20%	All places
Bronzor	Walking in tall grass or a cave	8	20%	All places

SoulSilver: 13 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	6 to 8	up to 25%	All places
Zubat	Walking in tall grass or a cave	7 to 9	up to 20%	All places
Geodude	Walking in tall grass or a cave	8	up to 20%	All places
Onix	Walking in tall grass or a cave	8	10%	All places
Goldeen	Fishing with a good rod	20	60%	All places
Goldeen	Fishing with an old rod	10	15%	All places
Goldeen	Fishing with a super rod	40	70%	All places
Seaking	Fishing with a super rod	40	10%	All places
Magikarp	Fishing with a good rod	20	40%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Magikarp	Fishing with a super rod	40	20%	All places
Wooper	Surfing	10 to 20	60%	All places
Quagsire	Surfing	10 to 25	40%	All places
Makuhita	Walking in tall grass or a cave	7	20%	All places
Absol	Walking in tall grass or a cave	8	20%	All places
Chingling	Walking in tall grass or a cave	7	20%	All places
Bronzor	Walking in tall grass or a cave	8	20%	All places

Area 3 of 3

Union Cave (B2F): 19 species across 5 versions

GoldSilverCrystalHeartGold and SoulSilver

Gold: 15 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	20	5%	All places
Raticate	Walking in tall grass or a cave	22	30%	All places
Zubat	Walking in tall grass or a cave	22	30%	All places
Golbat	Walking in tall grass or a cave	22	20%	All places
Tentacool	Surfing	15 to 19	60%	All places
Tentacruel	Surfing	20 to 24	10%	All places
Geodude	Walking in tall grass or a cave	21	10%	All places
Onix	Walking in tall grass or a cave	23	5%	All places
Krabby	Fishing with a good rod	20	up to 55%	All places
Krabby	Fishing with an old rod	10	15%	All places
Krabby	Fishing with a super rod	40	up to 60%	All places
Kingler	Fishing with a super rod	40	up to 10%	All places
Staryu	Fishing with a good rod	20	10%	All places
Staryu	Fishing with a super rod	40	30%	All places
Magikarp	Fishing with a good rod	20	up to 35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Lapras	Static encounter	20	100%	All places
Quagsire	Surfing	20 to 24	30%	All places
Corsola	Fishing with a good rod	20	up to 10%	All places
Corsola	Fishing with a super rod	40	up to 30%	All places

Silver: 15 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	20	5%	All places
Raticate	Walking in tall grass or a cave	22	30%	All places
Zubat	Walking in tall grass or a cave	22	30%	All places
Golbat	Walking in tall grass or a cave	22	20%	All places
Tentacool	Surfing	15 to 19	60%	All places
Tentacruel	Surfing	20 to 24	10%	All places
Geodude	Walking in tall grass or a cave	21	10%	All places
Onix	Walking in tall grass or a cave	23	5%	All places
Krabby	Fishing with a good rod	20	up to 55%	All places
Krabby	Fishing with an old rod	10	15%	All places
Krabby	Fishing with a super rod	40	180%	All places
Kingler	Fishing with a super rod	40	30%	All places
Staryu	Fishing with a good rod	20	10%	All places
Staryu	Fishing with a super rod	40	30%	All places
Magikarp	Fishing with a good rod	20	up to 35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Lapras	Static encounter	20	100%	All places
Quagsire	Surfing	20 to 24	30%	All places
Corsola	Fishing with a good rod	20	up to 10%	All places
Corsola	Fishing with a super rod	40	60%	All places

Crystal: 14 species
Species	Method	Levels	Chance	Game page
Raticate	Walking in tall grass or a cave	21	up to 10%	All places
Zubat	Walking in tall grass or a cave	22	up to 50%	All places
Golbat	Walking in tall grass or a cave	22	up to 30%	All places
Tentacool	Surfing	15 to 19	60%	All places
Tentacruel	Surfing	20 to 24	10%	All places
Geodude	Walking in tall grass or a cave	20	up to 5%	All places
Onix	Walking in tall grass or a cave	23	up to 5%	All places
Krabby	Fishing with a good rod	20	up to 55%	All places
Krabby	Fishing with an old rod	10	15%	All places
Krabby	Fishing with a super rod	40	up to 60%	All places
Kingler	Fishing with a super rod	40	up to 10%	All places
Staryu	Fishing with a good rod	20	10%	All places
Staryu	Fishing with a super rod	40	30%	All places
Magikarp	Fishing with a good rod	20	up to 35%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Lapras	Static encounter	20	100%	All places
Quagsire	Surfing	20 to 24	30%	All places
Quagsire	Walking in tall grass or a cave	22	20%	All places
Corsola	Fishing with a good rod	20	up to 10%	All places
Corsola	Fishing with a super rod	40	up to 30%	All places

HeartGold and SoulSilver: 19 species
Species	Method	Levels	Chance	Game page
Rattata	Walking in tall grass or a cave	20	5%	All places
Raticate	Walking in tall grass or a cave	22	up to 20%	All places
Zubat	Walking in tall grass or a cave	22	up to 20%	All places
Golbat	Walking in tall grass or a cave	22	20%	All places
Tentacool	Surfing	10 to 20	60%	All places
Tentacruel	Surfing	15 to 25	10%	All places
Geodude	Walking in tall grass or a cave	21	10%	All places
Onix	Walking in tall grass or a cave	23	5%	All places
Krabby	Fishing with a good rod	20	50%	All places
Krabby	Fishing with an old rod	10	15%	All places
Krabby	Fishing with a super rod	40	60%	All places
Kingler	Fishing with a super rod	40	10%	All places
Staryu	Fishing with a good rod	20	10%	All places
Staryu	Fishing with a super rod	40	30%	All places
Magikarp	Fishing with a good rod	20	40%	All places
Magikarp	Fishing with an old rod	10	85%	All places
Lapras	Static encounter	20	100%	All places
Quagsire	Surfing	15 to 25	30%	All places
Corsola	Fishing with a good rod	20	up to 10%	All places
Corsola	Fishing with a super rod	40	up to 30%	All places
Makuhita	Walking in tall grass or a cave	22	20%	All places
Absol	Walking in tall grass or a cave	22	20%	All places
Chingling	Walking in tall grass or a cave	22	20%	All places
Bronzor	Walking in tall grass or a cave	22	20%	All places