88: Grimer 90: Shellder

Muk

89: Muk

Kanto

	HeartGold	SoulSilver	FireRed	LeafGreen	Crystal	Gold	Silver	Yellow	Red	Blue
Walking in tall grass or a cave
Pokémon Mansion 1F				5% L32					1% L39	4% L37
Pokémon Mansion 2F				5% L32				5% L35–38	1% L37	4% L39
Pokémon Mansion 3F				5% L32				5% L38–41	1% L42	15% L38–40
Pokémon Mansion B1F				5% L34				10% L41	1% L42	10% L40
Power Plant								5% L33–37
Route 16	5% L30	5% L30			+5% L30 +5% L30 +5% L30	+5% L30 +5% L30 +5% L30	+5% L30 +5% L30 +5% L30
Route 17	5% L32 +10% L30	5% L32 +10% L30			+5% L33 +5% L33 +5% L33	+5% L32 +5% L32 +15% L30–32	+5% L32 +5% L32 +15% L30–32
Route 18	5% L30 +10% L29	5% L30 +10% L29			+5% L30 +5% L30 +5% L30	+5% L30 +5% L30 +5% L30	+5% L30 +5% L30 +5% L30
	HeartGold	SoulSilver	FireRed	LeafGreen	Crystal	Gold	Silver	Yellow	Red	Blue
Surfing
Celadon City	10% L15	10% L15			10% L15–19	10% L15–19	10% L15–19

Unova

	Black 2	White 2	Black	White
Walking in tall grass or a cave
Route 9	5% L40	5% L40
	Black 2	White 2	Black	White
Walking in dark grass
Route 9	5% L44	5% L44
	Black 2	White 2	Black	White
Fishing in dark spots
Castelia Sewers	20% L50–70	20% L50–70
Castelia Sewers unknown area 38	20% L70	20% L70
	Black 2	White 2	Black	White
Surfing in dark spots
Castelia Sewers	5% L5–20	5% L5–20
Castelia Sewers unknown area 38	5% L5–20	5% L5–20