Route 16: 12 species in 1 game

Road 16: 12 species across 2 versions

X: 12 species
Species	Method	Levels	Chance	Game page
Poliwag	Fishing with an old rod	15	100%	All places
Poliwhirl	Fishing with a good rod	25	35%	All places
Poliwhirl	Fishing with a super rod	35	65%	All places
Weepinbell	Walking in yellow flowers	35 to 36	20%	All places
Murkrow	Encountering 5 pokemon within grass, flowers, or within a cave	18	60%	All places
Lombre	Surfing	34 to 36	66%	All places
Floatzel	Surfing	34 to 36	34%	All places
Floatzel	Walking in yellow flowers	35 to 36	20%	All places
Skorupi	Walking in yellow flowers	34 to 35	20%	All places
Basculin	Fishing with a super rod	35	35%	All places
Foongus	Encountering 5 pokemon within grass, flowers, or within a cave	18	35%	All places
Foongus	Walking on rough terrain	34 to 36	20%	All places
Foongus	Walking in yellow flowers	34 to 36	20%	All places
Klefki	Encountering 5 pokemon within grass, flowers, or within a cave	19	5%	All places
Klefki	Walking on rough terrain	34 to 35	9%	All places
Klefki	Walking in yellow flowers	34 to 36	10%	All places
Phantump	Walking on rough terrain	35	10%	All places
Phantump	Walking in yellow flowers	35	10%	All places
Pumpkaboo	Walking on rough terrain	34 to 35	30%	All places

Y: 12 species
Species	Method	Levels	Chance	Game page
Poliwag	Fishing with an old rod	15	100%	All places
Poliwhirl	Fishing with a good rod	25	35%	All places
Poliwhirl	Fishing with a super rod	35	65%	All places
Weepinbell	Walking in yellow flowers	35 to 36	20%	All places
Murkrow	Encountering 5 pokemon within grass, flowers, or within a cave	18	60%	All places
Lombre	Surfing	34 to 36	66%	All places
Floatzel	Surfing	34 to 36	34%	All places
Floatzel	Walking in yellow flowers	35 to 36	20%	All places
Skorupi	Walking in yellow flowers	34 to 35	20%	All places
Basculin	Fishing with a good rod	25	65%	All places
Foongus	Encountering 5 pokemon within grass, flowers, or within a cave	18	35%	All places
Foongus	Walking on rough terrain	34 to 36	20%	All places
Foongus	Walking in yellow flowers	34 to 36	20%	All places
Klefki	Encountering 5 pokemon within grass, flowers, or within a cave	19	5%	All places
Klefki	Walking on rough terrain	34 to 35	9%	All places
Klefki	Walking in yellow flowers	34 to 36	10%	All places
Phantump	Walking on rough terrain	35	10%	All places
Phantump	Walking in yellow flowers	35	10%	All places
Pumpkaboo	Walking on rough terrain	34 to 35	30%	All places