Before you travel through the Viridian Forest you should head west out of Viridian City to visit this route. You'll get to battle your rival again and also have the opportunity to catch a Mankey, the only fighting type you'll have access to until you reach the Rock Tunnel later in the game. If you're patient you can also catch a Spearow, which is a great alternative to Pidgey if you're looking for a flying type for your party. Don't forget to weaken a Pokémon in battle before using a Poké Ball on it, or else it will be able to break free and you'll have to try again.
Pokémon found
| FireRed | Level | Encounter Rate | LeafGreen | Level | Encounter Rate |
|---|---|---|---|---|---|
 Rattata
|
2-5 | 45% | Rattata
|
2-5 | 45% |
 Mankey
|
2-5 | 45% | Mankey
|
2-5 | 45% |
 Spearow
|
3-5 | 10% | Spearow
|
3-5 | 10% |
| Surfing | |||||
 Psyduck
|
20-40 | 100% |  Slowpoke
|
20-40 | 100% |
| Old Rod | |||||
 Magikarp
|
5 | 100% | Magikarp
|
5 | 100% |
| Good Rod | |||||
 Poliwag
|
5-15 | 60% | Poliwag
|
5-15 | 60% |
| Magikarp
|
5-15 | 20% | Magikarp
|
5-15 | 20% |
 Goldeen
|
5-15 | 20% | Goldeen
|
5-15 | 20% |
| Super Rod | |||||
| Poliwag
|
15-25 | 40% | Poliwag
|
15-25 | 40% |
 Poliwhirl
|
20-30 | 40% | Poliwhirl
|
20-30 | 40% |
 Gyarados
|
15-25 | 15% | Gyarados
|
15-25 | 15% |
| Psyduck
|
15-35 | 5% | Slowpoke
|
15-35 | 5% |
New Pokémon
Spearow may not have a third stage of evolution like Pidgey, but it is a bit rarer, a bit stronger, and a lot cooler. It also starts off with a bigger advantage than Pidgey versus bug types since it starts with Peck, a Flying type move. If you have a Bulbasaur or Squirtle you should definitely pick up one of the Bug-Stomping flyers before you enter Viridian Forest.
Commonly found early on in Route #22, you'll find that Mankey's powerful fighting attacks to be very useful against Normal and Rock-type enemies. They learn their first Fighting-type technique, Low Kick, at Level 6. You should get one if you have a Charmander, as Mankey will have a much easier time damaging the Rock-type Pokémon of the first gym.
Rival Battle #1
If you chose Charmander:
| FireRed and LeafGreen | |
|---|---|
| Trainer | Pokemon |
 Rival Blue Reward:  144 |
|
If you chose Squirtle:
| FireRed and LeafGreen | |
|---|---|
| Trainer | Pokemon |
Rival Blue Reward: 144 |
|
If you chose Bulbasaur:
| FireRed and LeafGreen | |
|---|---|
| Trainer | Pokemon |
Rival Blue Reward: 144 |
|
You'll find your rival on route 22 after the first tall grass, but before the second. Your rival will only have two Pokémon, Pidgey and the starter, both at level 9. Pidgey can be easily defeated with a Thundershock (Pikachu can be found in Viridian Forest). Bulbasaur and Charmander can be beaten with Peck or Gust by Spearow or Pidgey; Squirtle can be beaten easily with Thundershock.