Pokedex Randomizer

Phase 8 section

Pokemon Yellow Power Plant, Route 21, and Viridian Gym Walkthrough

Power Plant, Route 21, and Viridian Gym section for the Pokemon Yellow walkthrough with wild Pokemon, trainers, items, hidden items, coordinates, and boss strategy.

By Damodar Sharma Updated June 23, 2026 Walkthrough

Optional Zapdos and Power Plant loot, Surf north/south Route 21, then defeat Giovanni in the reopened Viridian Gym. This page is a standalone section for Phase 8: Earth Badge, with source-backed Yellow encounter, trainer, item, hidden item, and boss data.

Source maps

Power Plant, Route 21, and Viridian Gym.

Wild rows26 Trainers18 Items9

Route plan

Power Plant is optional but important for completion and Electric catches. Viridian Gym is Ground-type heavy and rewards Water/Grass coverage.

Wild Pokemon

Each area below has its own table, split into encounter method bands: tall grass / cave floor, Surfing, the three rods, then gift, trade, prize, and static rows. Grass and Surf rows merge every Gen I wild slot for a species and show the combined odds out of 256 (slot rates 51/256, 51/256, 39/256, 25/256, 25/256, 25/256, 13/256, 13/256, 11/256, and 3/256). Generation I has no time-of-day split, so no rate varies with the clock; a — note means the row needs nothing beyond reaching the area.

Power Plant

Power Plant wild Pokemon by encounter method, levels, rate, and requirements
PokémonLevelsRateNotes
Tall grass / cave floor
Magnemite Yellow sprite Magnemite 30-3540%—
Magneton Yellow sprite Magneton 33-3820%—
Voltorb Yellow sprite Voltorb 33-3720%—
Grimer Yellow sprite Grimer 33-3715%—
Muk Yellow sprite Muk 33-375.5%—
Static item-ball Pokemon
Voltorb Yellow sprite Voltorb 40StaticLooks like an item ball before battle.
Voltorb Yellow sprite Voltorb 40StaticLooks like an item ball before battle.
Voltorb Yellow sprite Voltorb 40StaticLooks like an item ball before battle.
Electrode Yellow sprite Electrode 43StaticLooks like an item ball before battle.
Voltorb Yellow sprite Voltorb 40StaticLooks like an item ball before battle.
Voltorb Yellow sprite Voltorb 40StaticLooks like an item ball before battle.
Electrode Yellow sprite Electrode 43StaticLooks like an item ball before battle.
Voltorb Yellow sprite Voltorb 40StaticLooks like an item ball before battle.
Static Pokemon
Zapdos Yellow sprite Zapdos 50StaticInteract with the overworld Pokemon.

Route 21

Route 21 wild Pokemon by encounter method, levels, rate, and requirements
PokémonLevelsRateNotes
Tall grass / cave floor
Pidgey Yellow sprite Pidgey 11-1755%—
Rattata Yellow sprite Rattata 13-1530%—
Pidgeotto Yellow sprite Pidgeotto 15-1911%—
Raticate Yellow sprite Raticate 155.1%—
Surfing
Tentacool Yellow sprite Tentacool 5-40100%—
Fishing — Old Rod
Magikarp Yellow sprite Magikarp 5100%Any fishable water tile.
Fishing — Good Rod
Goldeen Yellow sprite Goldeen 1050%Any fishable water tile after getting Good Rod.
Poliwag Yellow sprite Poliwag 1050%Any fishable water tile after getting Good Rod.
Fishing — Super Rod
Tentacool Yellow sprite Tentacool 1525%Yellow Super Rod slot table.
Staryu Yellow sprite Staryu 2025%Yellow Super Rod slot table.
Tentacool Yellow sprite Tentacool 3025%Yellow Super Rod slot table.
Tentacruel Yellow sprite Tentacruel 3025%Yellow Super Rod slot table.

Trainers

Route order Trainer Team Reward Optional / rematch note
1. Route 21 (4, 24)Fisherman trainer spriteFishermanParty #7
Seaking Yellow sprite Seaking Lv. 28 Goldeen Yellow sprite Goldeen Lv. 28 Seaking Yellow sprite Seaking Lv. 28 Seaking Yellow sprite Seaking Lv. 28
$980One-time trainer; no rematch in Yellow.
2. Route 21 (6, 25)Fisherman trainer spriteFishermanParty #9
Magikarp Yellow sprite Magikarp Lv. 27 Magikarp Yellow sprite Magikarp Lv. 27 Magikarp Yellow sprite Magikarp Lv. 27 Magikarp Yellow sprite Magikarp Lv. 27 Magikarp Yellow sprite Magikarp Lv. 27 Magikarp Yellow sprite Magikarp Lv. 27
$945One-time trainer; no rematch in Yellow.
3. Route 21 (10, 31)Swimmer trainer spriteSwimmerParty #12
Seadra Yellow sprite Seadra Lv. 33 Tentacruel Yellow sprite Tentacruel Lv. 33
$165One-time trainer; no rematch in Yellow.
4. Route 21 (12, 30)Cue Ball trainer spriteCue BallParty #9
Tentacool Yellow sprite Tentacool Lv. 31 Tentacool Yellow sprite Tentacool Lv. 31 Tentacruel Yellow sprite Tentacruel Lv. 31
$775One-time trainer; no rematch in Yellow.
5. Route 21 (16, 63)Swimmer trainer spriteSwimmerParty #13
Starmie Yellow sprite Starmie Lv. 37
$185One-time trainer; no rematch in Yellow.
6. Route 21 (5, 71)Swimmer trainer spriteSwimmerParty #14
Staryu Yellow sprite Staryu Lv. 33 Wartortle Yellow sprite Wartortle Lv. 33
$165One-time trainer; no rematch in Yellow.
7. Route 21 (15, 71)Swimmer trainer spriteSwimmerParty #15
Poliwhirl Yellow sprite Poliwhirl Lv. 32 Tentacool Yellow sprite Tentacool Lv. 32 Seadra Yellow sprite Seadra Lv. 32
$160One-time trainer; no rematch in Yellow.
8. Route 21 (14, 56)Fisherman trainer spriteFishermanParty #8
Shellder Yellow sprite Shellder Lv. 31 Cloyster Yellow sprite Cloyster Lv. 31
$1,085One-time trainer; no rematch in Yellow.
9. Route 21 (17, 57)Fisherman trainer spriteFishermanParty #10
Seaking Yellow sprite Seaking Lv. 33 Goldeen Yellow sprite Goldeen Lv. 33
$1,155One-time trainer; no rematch in Yellow.
10. Viridian Gym (2, 1)Giovanni trainer spriteGiovanniParty #3
Dugtrio Yellow sprite Dugtrio Lv. 50 Persian Yellow sprite Persian Lv. 53 Nidoqueen Yellow sprite Nidoqueen Lv. 53 Nidoking Yellow sprite Nidoking Lv. 55 Rhydon Yellow sprite Rhydon Lv. 55
$5,445One-time trainer; no rematch in Yellow.
11. Viridian Gym (12, 7)Cooltrainer M trainer spriteCooltrainer MParty #9
Sandslash Yellow sprite Sandslash Lv. 39 Dugtrio Yellow sprite Dugtrio Lv. 39
$1,365One-time trainer; no rematch in Yellow.
12. Viridian Gym (11, 11)Blackbelt trainer spriteBlackbeltParty #6
Machop Yellow sprite Machop Lv. 40 Machoke Yellow sprite Machoke Lv. 40
$1,000One-time trainer; no rematch in Yellow.
13. Viridian Gym (10, 7)Tamer trainer spriteTamerParty #3
Rhyhorn Yellow sprite Rhyhorn Lv. 43
$1,720One-time trainer; no rematch in Yellow.
14. Viridian Gym (3, 7)Blackbelt trainer spriteBlackbeltParty #7
Machoke Yellow sprite Machoke Lv. 43
$1,075One-time trainer; no rematch in Yellow.
15. Viridian Gym (13, 5)Cooltrainer M trainer spriteCooltrainer MParty #10
Rhyhorn Yellow sprite Rhyhorn Lv. 43
$1,505One-time trainer; no rematch in Yellow.
16. Viridian Gym (10, 1)Blackbelt trainer spriteBlackbeltParty #8
Machoke Yellow sprite Machoke Lv. 38 Machop Yellow sprite Machop Lv. 38 Machoke Yellow sprite Machoke Lv. 38
$950One-time trainer; no rematch in Yellow.
17. Viridian Gym (2, 16)Tamer trainer spriteTamerParty #4
Arbok Yellow sprite Arbok Lv. 39 Tauros Yellow sprite Tauros Lv. 39
$1,560One-time trainer; no rematch in Yellow.
18. Viridian Gym (6, 5)Cooltrainer M trainer spriteCooltrainer MParty #1
Nidorino Yellow sprite Nidorino Lv. 39 Nidoking Yellow sprite Nidoking Lv. 39
$1,365One-time trainer; no rematch in Yellow.

Items And Hidden Items

Item Type Area / direction Coordinate Requirement
CarbosVisible item ballVisible item ball at (7, 25) in Power Plant.(7, 25)Reach this tile; HMs or story flags may be needed for late-game dungeons.
HP UpVisible item ballVisible item ball at (28, 3) in Power Plant.(28, 3)Reach this tile; HMs or story flags may be needed for late-game dungeons.
Rare CandyVisible item ballVisible item ball at (34, 3) in Power Plant.(34, 3)Reach this tile; HMs or story flags may be needed for late-game dungeons.
TM25 ThunderVisible item ballVisible item ball at (26, 32) in Power Plant.(26, 32)Reach this tile; HMs or story flags may be needed for late-game dungeons.
TM33 ReflectVisible item ballVisible item ball at (20, 32) in Power Plant.(20, 32)Reach this tile; HMs or story flags may be needed for late-game dungeons.
ReviveVisible item ballVisible item ball at (16, 9) in Viridian Gym.(16, 9)Reach this tile; HMs or story flags may be needed for late-game dungeons.
Max ElixerHidden itemHidden on the searchable tile at (17, 16) in Power Plant.(17, 16)Press A on the hidden tile or use the Itemfinder nearby.
PP UpHidden itemHidden on the searchable tile at (12, 1) in Power Plant.(12, 1)Press A on the hidden tile or use the Itemfinder nearby.
TM27 FissureGym rewardDefeat Giovanni for the Earth Badge.-Defeat Giovanni for the Earth Badge.

Boss Strategy

Boss / branch Team Reward Danger notes Practical counters
Giovanni trainer spriteGiovanniGiovanni - Viridian Gym
Dugtrio Yellow sprite Dugtrio Lv. 50 Persian Yellow sprite Persian Lv. 53 Nidoqueen Yellow sprite Nidoqueen Lv. 53 Nidoking Yellow sprite Nidoking Lv. 55 Rhydon Yellow sprite Rhydon Lv. 55
$5,445Rhydon is level 50 and the badge gate before Victory Road.Surf, Razor Leaf, Ice Beam, and strong Water/Grass coverage sweep. Watch Dugtrio's Speed if you bring frail Electric or Fire Pokemon.

Completion Checklist

  • Catch Zapdos if desired.
  • Clear Route 21 trainers/wilds.
  • Defeat Giovanni for Earth Badge.
  • Verify the Yellow encounter rows before leaving if you are filling the Pokedex.
  • Use the item rows as a visible-item and hidden-item sweep before moving to the next section.

Sources

  • pret/pokeyellow: wild encounters, trainer parties, trainer money, map object events, hidden event items, rods, trades, and prize Pokemon.
  • Encounter odds aggregate the Gen I ten-slot rates: 51/256, 51/256, 39/256, 25/256, 25/256, 25/256, 13/256, 13/256, 11/256, and 3/256.
  • Yellow is a single-game guide with no day/night encounter split; each area table groups species under method bands with Levels, Rate, and Notes columns.

Related articles

Pokemon Yellow Walkthrough HubPhase 8: Earth BadgePrevious: Cinnabar GymNext: Route 23 and Victory Road