Walkthrough
With the Vermilion City Gym now defeated, the next place to head is east of Vermilion City on Route 11. This path is full of both Wild Pokemon and Pokemon Trainers, and it also has access to Diglett's Cave. If you continue east on Route 11, you will soon reach Route 12. However, since a sleeping Pokemon will be blocking the path, the next logical place to head is through Diglett's Cave.
Nidorino (FireRed): Other Trainer Requests A Nidorina In Return
Nidorina (LeafGreen): Other Trainer Requests A Nidorino In Return
Wild Pokemon
Grasses:
Ekans(FireRed)/Sandshrew(LeafGreen) (40%): Levels 12-15
Spearow (35%): Levels 13-17
Drowzee (25%): Levels 11-15
Surfing:
Tentacool (100%): Levels 5-40
Magikarp (100%): Level 5
Horsea(FireRed)/Krabby(LeafGreen) (60%): Levels 5-15
Krabby(FireRed)/Horsea(LeafGreen) (20%): Levels 5-15
Magikarp (20%): Levels 5-15
Horsea(FireRed)/Krabby(LeafGreen) (84%): Levels 15-35
Gyarados (15%): Levels 15-25
Psyduck(FireRed)/Slowpoke(LeafGreen) (1%): Levels 25-35
Pokemon Trainers
Youngster Eddie: Level 31 Ekans
Gamer Hugo: Level 18 Poliwag, Level 18 Horsea
Engineer Bernie: Level 18 Magnemite, Level 18 Magnemite, Level 18 Magneton
Gamer Jasper: Level 18 Bellsprout, Level 18 Oddish
Youngster Dave: Level 18 Nidoran Male, Level 18 Nidorino
Youngster Dillion: Level 19 Sandshrew, Level 19 Zubat
Engineer Braxton: Level 21 Magnemite
Youngster Yasu: Level 17 Rattata, Level 17 Rattata, Level 17 Raticate
Gamer Darian: Level 18 Growlithe, Level 18 Vulpix
Gamer Dirk: Level 18 Voltorb, Level 18 Magnemite
Pokemon Trainers - VS Seeker Rematch
Engineer Bernie: Level 28 Magneton, Level 28 Magneton, Level 28 Magneton
Youngster Yasu: Level 22 Rattata, Level 22 Raticate, Level 22 Raticate
Youngster Yasu: Level 47 Raticate, Level 47 Raticate, Level 47 Raticate
Gamer Darian: Level 29 Growlithe, Level 29 Vulpix
Items
Great Ball: On Ground
Awakening: On Ground
X Defend: On Ground
Escape Rope: ItemFinder
ItemFinder: Gift From Professor Oak's Aide