One floor: Ilex Forest.
| Pokémon | How | Level | Chance | When |
|---|---|---|---|---|
| Caterpie | Walk | 5–6 | 60% | Morning, Day · Gold, Crystal only |
| Kakuna | Walk | 5–7 | 30% | Morning, Day · Silver, Crystal only |
| Metapod | Walk | 5–7 | 30% | Morning, Day · Gold, Crystal only |
| Oddish | Walk | 5–7 | 60% | Night |
| Paras | Walk | 5–6 | 15% | |
| Venonat | Walk | 5 | 30% | Night · Crystal only |
| Weedle | Walk | 5–6 | 60% | Morning, Day · Silver, Crystal only |
| Zubat | Walk | 5–6 | 25% | Gold, Silver only |
| Hoothoot | Walk | 7 | 5% | Night · Crystal only |
| Pidgey | Walk | 7 | 5% | Morning, Day · Crystal only |
| Psyduck | Walk | 7 | 10% | Night · Crystal only |
| Beedrill | Headbutt | 10 | 5% | Silver, Crystal only |
| Butterfree | Headbutt | 10 | 5% | Gold, Crystal only |
| Caterpie | Headbutt | 10 | 65% | Gold, Crystal only |
| Exeggcute | Headbutt | 10 | 15% | Gold, Silver only |
| Hoothoot | Headbutt | 10 | 50% | Crystal only |
| Kakuna | Headbutt | 10 | 15% | Silver, Crystal only |
| Metapod | Headbutt | 10 | 15% | Gold, Crystal only |
| Noctowl | Headbutt | 10 | 10% | Crystal only |
| Pineco | Headbutt | 10 | 30% | |
| Weedle | Headbutt | 10 | 65% | Silver, Crystal only |
| Psyduck | Surf | 10–19 | 90% | |
| Golduck | Surf | 15–19 | 10% | |
| Magikarp | Old Rod | 10 | 85% | |
| Poliwag | Old Rod | 10 | 15% | |
| Magikarp | Good Rod | 20 | 35% | |
| Poliwag | Good Rod | 20 | 65% | |
| Magikarp | Super Rod | 40 | 20% | |
| Poliwag | Super Rod | 40 | 80% | |
| Celebi | Static Encounter | 30 | 100% | Crystal only · Virtual Console only |
Ilex Forest on the Johto & Kanto map · Pokémon Gold, Silver & Crystal interactive map (Johto & Kanto)