88: Grimer 90: Shellder

Muk

89: Muk

Kanto

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