94: Gengar 96: Drowzee

Onix

95: Onix

Kanto

	HeartGold	SoulSilver	FireRed	LeafGreen	Yellow	Red	Blue
Walking in tall grass or a cave
Rock Tunnel 1F			5% L13–15	5% L13–15
Rock Tunnel B1F			10% L13–17	10% L13–17
Rock Tunnel B1F	+20% L16	+20% L16				5% L13–15	5% L13–15
Rock Tunnel B2F					10% L14–22	9% L13–17	9% L13–17
Sevault Canyon			5% L54	5% L54
Victory Road 1F					10% L43–45	30% L36–42	30% L36–42
Victory Road 1F			30% L40–46
Victory Road 1F	15% L34–36	15% L34–36
Victory Road 1F				30% L40–46
Victory Road 2F					10% L45–47	30% L36–42	30% L36–42
Victory Road 2F	15% L34–36	15% L34–36
Victory Road 2F				20% L45–48
Victory Road 2F			20% L45–48
Victory Road 3F	15% L34–36	15% L34–36
Victory Road 3F					10% L49	20% L42–45	20% L42–45
Victory Road 3F				30% L40–46
Victory Road 3F			30% L40–46

Johto

	HeartGold	SoulSilver
Walking in tall grass or a cave
Mt. Silver 1F	20% L42 +10% L42	20% L42 +10% L42
Mt. Silver mountainside	20% L48 +10% L48	20% L48 +10% L48
Route 47 inside cave	+10% L20	+10% L20
Union Cave 1F	5% L6	5% L6
Union Cave B1F	10% L8	10% L8
Union Cave B2F	5% L23	5% L23

Sinnoh

	Platinum	Diamond	Pearl
Walking in tall grass or a cave
Iron Island 1F	10% L31–33	10% L32–33	10% L32–33
Iron Island B1F left	10% L31–33	10% L32–33	10% L32–33
Iron Island B1F right	10% L31–33	10% L32–33	10% L32–33
Iron Island B2F left	20% L32	30% L32–33	30% L32–33
Iron Island B2F right	20% L32	30% L31–33	30% L31–33
Iron Island B3F	+20% L32	30% L32–33	30% L32–33
Oreburgh Mine 1F	10% L6–8	10% L8	10% L8
Oreburgh Mine B1F	10% L7–9	10% L9	10% L9
Snowpoint Temple 1F		15% L50–52	15% L50–52
Snowpoint Temple B1F		5% L52–53	5% L52–53
Snowpoint Temple B2F		5% L52–53	5% L52–53
Snowpoint Temple B3F		5% L52–53	5% L52–53
Stark Mountain entrance		5% L54	5% L54
Stark Mountain inside		5% L56	5% L56
Victory Road 1F	20% L41–42	10% L44	10% L44
Victory Road 2F	5% L42	10% L45	10% L45
Victory Road B1F	10% L42
Victory Road inside	20% L48–50	10% L50	10% L50
Victory Road inside exit	20% L48–50	10% L50	10% L50
Wayward Cave 1F	11% L18–20 +4% L18 +4% L18 +4% L18 +4% L18 +4% L18
Wayward Cave B1F	11% L18–20 +4% L18 +4% L18 +4% L18 +4% L18 +4% L18