Fuchsia Gym · Gym 5

How to beat Koga in Pokemon Yellow

Yellow’s Koga is a level spike: Venonat 44 / 46 / 48 and Venomoth 50, all armed with Toxic. Navigate the invisible-wall maze, bring Psychic (or strong Flying), stock Antidotes, and treat this like a mini Elite Four room—not a normal mid-game gym.

Leader: Koga Venonat ×3 Venomoth Lv.50 Best: Psychic Invisible walls Soul Badge + TM06
Venonat
Venonat · 44–48
Venomoth
Venomoth · 50

Fast Answer

Psychic spam + Antidotes

Train into the mid-40s to 50, lead with Kadabra / Hypno / Mr. Mime (or any special attacker packing Psychic), and KO through Toxic turns with Full Heals ready. Flying STAB also hits Bug/Poison hard. Do not walk in at “Celadon gym levels”—Yellow Koga will outlevel a lazy party.

Fuchsia Gym fight

Koga’s Yellow team

Yellow-specific: four Bug/Poison mon peaking at 50. Red/Blue Koga guides with lower levels do not apply.

Slots 1–3

Venonat · 44 / 46 / 48

Bug Poison
  • Shared: Toxic on every set
  • 44: Tackle, Sleep Powder, Psychic tools
  • 46: Psybeam / Supersonic pressure
  • 48: Double-Edge + Sleep Powder

Ace

Venomoth · Lv.50

Bug Poison
  • Key: Leech Life, Double Team, Psychic, Toxic
  • Threat: Evasion spam + special damage + bad poison
  • Answer: Hard Psychic KO; don’t stall into Double Team
Soul Badge Surf outdoors (w/ HM03) Gen 1 Speed badge boost TM06 Toxic

Soul Badge permits Surf outdoors once you have HM03. Gen 1 also applies a Speed badge boost in battle—see the gym tool for the full badge note. Practically: win before Toxic ends the run.

Counters

Psychic first, Flying second

Kadabra

Psychic attackers

KadabraHypnoMr. Mime
  • Psychic is super effective on the Poison half of every mon here.
  • Kadabra from Route 8 evolution of Abra (or prize Abra)—glass cannon but deletes Venonat.
  • Mr. Mime via in-game trade if you need a bulkier special wall—see the trades tool.
  • Alakazam is ideal but needs a trade evolution; Kadabra is enough if levels match.
Gyarados

Flying / other plans

GyaradosPidgeotFearow
  • Flying is 2× into Bug and still fine into Poison—strong secondary STAB.
  • Fire is 2× into every Bug/Poison member: Poison is neutral to Fire while Bug is weak.
  • Ground does not stop Toxic; Nidoking can hit but is not “safe mode.”
  • Never rely on Normal-only spam while poisoned—KOs race the Toxic clock.

Gym puzzle

Invisible-wall maze

  • Walls are mostly invisible; dotted floor edges hint the outline.
  • Trace the outside lanes first, then work inward toward Koga.
  • Jugglers and Tamers sit on wrong turns—Psychic still answers most of them, but Hypno/Kadabra wars can waste PP.
  • Use the site map overlay if you keep looping; save before long maze attempts on Nuzlocke files.

Optional trainers include multiple Psychic users (Drowzee / Kadabra / Hypno)—ironic warm-ups before the Poison leader. Links start at Juggler #7 and neighbors in the trainer archive.

Suggested order

Fuchsia block & badge order

  1. Finish Celadon / Tower / hideout arcs as your run prefers; grab a Psychic mon early if missing.
  2. Reach Fuchsia via Cycling Road; optional Safari Zone and Snorlax catches.
  3. Train to ~45–50—Safari, Routes 15–18, or gym trainers outside Koga.
  4. Solve the maze, heal, stock Antidotes / Full Heals / PP recovery.
  5. Defeat Koga; claim Soul Badge + TM06 Toxic.
  6. Collect HM03 Surf from the Safari Zone Secret House—no Warden quest is required. Returning the Gold Teeth to the Warden gives HM04 Strength instead.
  7. Sabrina can be before or after Koga in Yellow; many players hit Fuchsia when levels finally match this spike.

Checklist

Track Koga prep on this device

0 of 0 checked

Tips

Yellow-only gotchas

Wrong-version guides

If a page lists lower levels or a different Koga team, it is not Yellow. Trust Lv.44–50 Venonat/Venomoth.

Toxic clock

Bad poison escalates. Switch, heal, or finish—never soft-stall with setup moves into three more Toxics.

Double Team Venomoth

Do not let the ace stack evasion. Keep pressing Psychic; X Accuracy is a luxury, not required if you one-shot range.

Nuzlocke level caps

Hardcore runs often set Koga’s cap near 50—see the Nuzlocke guide for Yellow caps.

Linked tools