Legendary catch · Cerulean Cave
How to catch Mewtwo in Pokemon Yellow
Mewtwo is a one-time Lv.70 static on Cerulean Cave B1F (Psychic, catch rate 3). Become Champion so the Unknown Dungeon opens, Surf and ladder to B1F, save at the monster sprite, then spend the Master Ball (Silph Co. 11F) or chip through Recover with sleep/freeze + Ultra Balls.
Fast answer
Champion · B1F · Master or Ultra
Finish the Elite Four and Champion. Enter Cerulean Cave from northwest Cerulean City, bring Surf, work through 1F / 2F to the B1F warp, then save in front of the Lv.70 monster. Catch rate is 3—the classic plan is Master Ball from Silph Co. 11F; otherwise sleep/freeze, chip carefully around Recover, and throw Ultra Balls. Floor loot and wilds: Cerulean Cave guide.
Interactive tool
Catch prep readiness
Track postgame gates and kit on this device before a low-HP save on B1F.
Prep score
0 / 6Beat the Champion, pack Surf and balls, reach B1F, then save at Mewtwo.
Route to the static
From Champion to Cerulean Cave B1F
1. Become Champion
Clear Lorelei, Bruno, Agatha, Lance, and the Champion Rival. Enter the Hall of Fame so the Unknown Dungeon unlocks.
2. Secure the Master Ball (optional)
After defeating Giovanni on Silph Co. 11F, the president gives the only story Master Ball. Saving it for Mewtwo is the classic plan.
3. Enter Cerulean Cave
From northwest Cerulean City, enter the cave. Bring Surf, healing items, and Escape Rope. There is no Center inside.
4. Ladders to B1F, then save
Use 1F/2F ladders and water tiles to reach the B1F warp. Mewtwo is the fixed monster on B1F—save before contact, then open the catch tool.
Catch odds tool
Gen 1 ball odds for Mewtwo
Uses the same Yellow catch model as the site Catch Planner (catch rate 3, ball factors, status bonuses). Default max HP ≈240 is a mid-DV Lv.70 estimate (base 106 HP)—adjust if your calc differs. Master Ball is always 100%.
Approx. catch chance
—Pick Master Ball for a free catch, or Ultra Ball + sleep/freeze for the CR 3 plan.
Battle profile
What you are fighting
Mewtwo · #150
- Location: Cerulean Cave B1F
- Method: Overworld static monster sprite
- Catch rate: 3
- Base stats: HP 106 · Atk 110 · Def 90 · Spe 130 · Spc 154 (total 590)
- Growth: Slow · base exp 220
Cerulean Cave B1F map
Mewtwo is a fixed monster object on B1F (not a ball). Nearby pickups include Ultra Balls, Max Revive, and Max Elixer—grab them if you still need kit.
Moves at the Lv.70 static
| Level | Move | Notes |
|---|---|---|
| Base | Swift | At static · never misses |
| Base | Psychic | At static · main STAB threat |
| 63 | Barrier | At static · Defense setup |
| 70 | Recover | At static · stall risk while catching |
| 75 | Mist | Later if raised |
| 81 | Amnesia | Later Special wall |
Matchup tips
- Gen 1 Bug is super effective, but practical damaging options are scarce. Beedrill can use Twineedle; Yellow Pinsir and Scyther do not learn a damaging Bug move to exploit the matchup.
- Ghost attacks do no damage to Psychic in Yellow, so do not bring them as a type-counter plan.
- Avoid long special wars: Special 154 + Psychic melts pure special sponges.
- Recover: Chip slowly; False Swipe is not in Yellow. Keep a strong physical attacker ready if the fight stalls.
- Barrier: Can blunt physical chip. Bring sleep and a controlled special or fixed-damage option, or use the Master Ball.
Checklist
Catch tracker (this device)
Play tips
Fewer reloads on CR 3 + Recover
Heal in Cerulean first
No Pokémon Center in the cave. Stock Full Restores, Revives, Escape Rope, and balls at Cerulean before the NW entrance.
Master Ball is the easy path
If you still have the Silph Master Ball, walking into Mewtwo and throwing it ends the fight. Save the Ultra Ball math for birds or completionist Ultra-only runs.
Recover extends Ultra attempts
When not using Master Ball, keep pressure so Recover does not undo your chip. Sleep/freeze still gives the best catch bonus.
Story can skip Mewtwo
Mewtwo is optional postgame. Diploma / 150-species goals care about ownership; the Champion path does not require the catch.
FAQ
Mewtwo catch questions
How do you catch Mewtwo in Pokemon Yellow?
Become Champion, enter Cerulean Cave, reach B1F, save at the Lv.70 static, then use the Master Ball or sleep/freeze + Ultra Balls (catch rate 3).
Where is Mewtwo?
On Cerulean Cave B1F (Unknown Dungeon). Open the map pin.
What level is Mewtwo?
Level 70, with Swift, Psychic, Barrier, and Recover already known. Confusion and Disable have been overwritten.
When does the cave open?
Only after you become Champion and enter the Hall of Fame. It is postgame-only.
Where is the Master Ball?
The Silph Co. 11F president gives it after you defeat Giovanni. See Master Ball and the Silph Co. guide.
Do I need Mewtwo to finish the game?
No. It is optional postgame content.
What if I faint it?
Load a save from before the battle. Do not overwrite that save after a KO if you still want Mewtwo on this file.
Where are the legendary birds?
Articuno (Seafoam), Zapdos (Power Plant), Moltres (Victory Road)—or the legendary hub.
Linked tools