Glitch guide · #151

Pokemon Yellow Mew glitch

There is no normal wild Mew in Yellow. The Trainer-Fly / long-range trainer glitch still works, and Yellow lets you do it earlier with a Viridian Forest Bug Catcher. The forced encounter species comes from the last foe’s Special stat—Mew needs Special 21.

Mew index 21 Default level 7 Catch rate 45 Psychic · all 100 base No normal encounter
Mew
Mew · Sp. index 21
Slowpoke
Slowpoke Lv.17 · Sp. 21

Fast Answer

Special 21, then return to the escape map

1) Start the glitch on a long-range trainer and leave with Escape Rope / Teleport / Fly before the fight. 2) Battle a trainer who must walk at least one tile to you (restores controls). 3) End a fight on a mon with Special 21—Yellow-friendly sources: Koffing Lv.12 (Mt. Moon Super Nerd), Slowpoke Lv.17 (Route 25 Youngster), or Shellder Lv.16 (Cerulean Gym Swimmer). 4) Return to the escape map without another battle. Close the auto Start menu → wild Level 7 Mew.

Yellow-only edge

Why Yellow searchers care about “early Mew”

Red/Blue usually wait for Fly or Abra Teleport. Yellow adds a long-range Bug Catcher in Viridian Forest, so you can force Mew after Pewter / Mt. Moon with Escape Ropes—before Cascade Badge and long before HM02. Save often: a mis-timed menu, talking face-to-face with the “walking” trainer, or any extra battle after Special 21 will desync the setup.

Species rule

Special = index number (Mew needs 21)

Trainer Pokemon use fixed DVs (Special DV 8) and no Stat Exp, so Special is deterministic. Formula: floor((Base + 8) × Level / 50) + 5.

Early Yellow

Koffing · Lv.12

Poison
  • Base Special 60 → Sp. 21
  • Source: Super Nerd #2, Mt. Moon B2F (last mon)
  • Link: Trainer card

Classic

Slowpoke · Lv.17

WaterPsychic
  • Base Special 40 → Sp. 21
  • Source: Youngster #6, Route 25 (only mon)
  • Link: Trainer card

Quick method

Shellder · Lv.16

Water
  • Base Special 45 → Sp. 21
  • Source: Swimmer #1, Cerulean Gym (last mon)
  • Link: Trainer card

Result

Wild Mew · Lv.7

Psychic
  • Index: 21 ($15)
  • Catch rate: 45 · stats 100 across the board
  • Level note: Growl on the Special-21 mon can lower encounter level (Attack stage)

Do not fight after Special 21

Any other battle overwrites the stored Special. Escape Rope / Fly / Teleport immediately after the right foe faints.

Walking trainers only

The mid-glitch trainer must walk ≥1 tile into you. Talking face-to-face softlocks the frozen-menu state.

Open Start at least once

Before re-entering the escape map, flash the Start menu so text-box ID 0 is safe (auto Start at the end is normal).

Yellow exclusive · earliest window

Early Viridian Forest method

Before Cascade Badge

Yellow’s Bug Catcher #15 in Viridian Forest is a long-range trainer. Combined with Mt. Moon B2F Super Nerd #2 (Grimer → Voltorb → Koffing Sp.21), you can finish Mew without Abra or Fly.

Long-range escape

Bug Catcher #15

  • Location: Viridian Forest
  • Party: Caterpie Lv.8, Metapod Lv.8
  • Leave undefeated until setup
  • Open trainer · Map

Special loader

Super Nerd #2

  • Location: Mt. Moon B2F fossils room
  • Party: Grimer 12, Voltorb 12, Koffing 12
  • Faint Koffing last
  • Open trainer · Map
  1. Skip Bug Catcher #15 on your first Forest pass (and leave one other walking trainer undefeated for later).
  2. Clear Pewter (see How to beat Brock), buy 2+ Escape Ropes at Pewter Mart, heal at the Pewter Center (sets Escape Rope return).
  3. Progress Route 3 / Mt. Moon. Keep the Super Nerd undefeated until ready. Optional: catch Butterfree (Sleep Powder) for the Mew fight.
  4. Return to Viridian Forest. Trigger Bug Catcher #15’s sight, hold Start so the menu opens, use Escape Rope before the battle. Exclamation may flash; you should warp to Pewter.
  5. With Start disabled, walk into your skipped trainer so they take ≥1 step. After that fight, the menu works again.
  6. Enter Mt. Moon B2F. Optionally open/close Start, then fight Super Nerd #2. Faint Grimer and Voltorb first; finish on Koffing. Optional Growl for lower Mew level.
  7. Without moving into grass, use Escape Rope again. Avoid any wild battle on Route 2—use paths with no grass where possible.
  8. Re-enter Viridian Forest. Start menu auto-opens → close it → wild Mew Lv.7. Status + balls; mark Mew in Pokedex / Catch Planner.
Viridian Forest map layout

Side effect · fossils

After this early setup, the Helix Fossil sprite can vanish. Dome Fossil still works; the Super Nerd may mime the other choice. You can also walk past fossil selection.

Save slots

Save before the Forest Escape Rope and before the Super Nerd fight. Softlocks usually mean you engaged a trainer face-to-face during the frozen-menu phase.

Party tip

Leave a free party slot. Sleep Powder / Sing plus a weak mon to chip HP makes catch rate 45 far less painful.

After Nugget Bridge

Quick Route 24 method

Needs Abra Teleport

Same glitch structure with a later long-range trainer: Jr. Trainer♂ #2 west of Nugget Bridge on Route 24, plus Cerulean Gym Swimmer #1 (Horsea → Shellder Sp.21). Yellow players must visit Bill and reach Route 5 grass for Abra (Abra is not on Route 24/25 in Yellow).

  1. Clear Nugget Bridge trainers you need, but leave Jr. Trainer♂ #2 undefeated. See also Charmander gift on Route 24.
  2. Visit Bill, open Cerulean, catch Abra on Route 5 near the Daycare grass. Heal at the Cerulean Center so Teleport returns there.
  3. Trigger Jr. Trainer♂ #2’s long-range sight, open Start, Teleport away before the fight.
  4. Walk a trainer into you (or use another undefeated walker) to restore controls, then challenge Swimmer #1. Faint Shellder last.
  5. Return to Route 24 without another battle. Auto Start → close → Mew Lv.7.

Mid-game standard

Classic Route 8 + Route 25 method

Needs Fly

The textbook setup: Gambler #5 under the Underground Path entrance on Route 8 (facing up), and Youngster #6 on Route 25 with a single Slowpoke Lv.17 (Sp.21).

  1. Stand under the Underground Path door on Route 8 so the Gambler is one tile off-screen. Save.
  2. Step down while holding Start. Menu opens as the Gambler scrolls on-screen. Fly to Cerulean (or any town) before he reaches you—the “!” may flash.
  3. Walk to Route 25. Engage Youngster #6 so he walks ≥1 tile. Beat Slowpoke.
  4. Fly toward Route 8 (Lavender → west is common). Flash Start if needed. Enter Route 8 → auto Start → Mew.
Route 25 map layout

Battle plan

Catching Level 7 Mew

Mew’s catch rate is 45—same ballpark as many mid-game species. At level 7 with full HP, raw balls can bounce a lot.

Status first

Sleep or freeze roughly doubles effective catch odds versus healthy Mew. Stun Spore / Sleep Powder / Sing are ideal.

Chip HP safely

Use a weak physical hit. Avoid OHKO specials—Mew’s Special is 100 base even at low level and can surprise you later, but level 7 is fragile to strong hits.

Balls

Great Balls if you have them; Ultra later. Stock up at Cerulean / Pewter marts. Track attempts in Catch Planner.

After the catch

Mew is tracked separately from the 150-species diploma goal on this site’s Pokedex. Import a save on Save Import or tick My Run when you own it.

Interactive

Mew glitch checklist

Checks stay on this device (localStorage). Pick one method path—you do not need every box.

0 of 10 checked

FAQ

Common Mew glitch questions

Is Mew “legit” this way?

It is a cartridge glitch, not a code. There is still no normal story encounter—Yellow’s Pokedex marks Mew as event-only for legitimate play.

Does MissingNo. still work?

The classic old-man / Cinnabar coast MissingNo. path is patched in Yellow. Mew glitch is a different exploit and still functions.

Can I transfer glitch Mew?

Virtual Console → Bank / Transporter often rejects glitch Mew unless OT/ID match official distributions. Plan to keep it on the Yellow save or emulator.

Can I get other species?

Yes—any Special value maps to a Gen I index. Special 21 is only required for Mew. Save before experiments; high Special can spawn glitch trainers.