Glitch Pokémon

MissingNo., a well-known glitch Pokémon

A glitch Pokémon is a collection of data that, due to programming oversights, a Pokémon game handles as if it were a Pokémon species.

Some glitch Pokémon have partially defined characteristics, such as "MissingNo." or "??????????". Another example of this is the learn-set data for a Generation IV Egg, where it learns Splash as a starting move, likely to prevent the game from crashing due to an invalid move being used.

In Generation I, a few glitch Pokémon are hazardous to the game, some glitch Pokémon may freeze the game if sent out on the opponent's side, and a few may even corrupt save data, depending on their Pokédex number and the version used. Note that glitch Pokémon with index numbers greater than 199 will usually bring up glitch Trainers if encountered directly in the wild. These glitch Pokémon cannot be obtained via a wild battle, and must be obtained using a different glitch from the Ditto glitch or old man glitch, such as evolution from another glitch Pokémon, trading an equivalent index number glitch Pokémon to another version, or by executing the Time Capsule exploit. Additionally, catching certain obtainable glitch Pokémon in Generation I may cause endless garbage Pokédex data to appear. To avoid this, the player must have activated a specific flag, if this is a hybrid glitch Pokémon, the flag is activated by either seeing a specific Pokémon or owning a specific Pokémon. Specific glitches (like the Super Glitch move or the ZZAZZ glitch) may cause the saved file to be corrupted or erased.

Conversely, in later generations, Glitch Pokémon are usually not hazardous, and generally only exist to fill empty space. The exception to this rule is the Bad Egg, which was added to the game to deter cheaters. Also, unlike the Generation I glitch Pokémon, which could be fought and captured using simple glitches, later Generation glitch Pokémon can generally only be seen by cheating.

Glitch Pokémon

Main article: List of glitch Pokémon

Trivia

• There are 39 MissingNo. with identifiers in between real Pokémon, which would add up to 190 Pokémon.
  • According to a fan's account of meeting Shigeki Morimoto, he confirmed that there were once 190 Pokémon planned for development in Pokémon Red and Green. MissingNo. is partially derived from blank entries in the various Pokémon data arrays. Most of its characteristics are derived from zeroed values in these arrays, including the pointer to its glitched base stats.
• The reason for the large number of glitch Pokémon in Generation I is because only 151 values correspond to valid Pokémon, while Pokémon species index numbers are stored in 8 bits allowing for up to 256 values. This leaves 105 values not corresponding to a valid Pokémon; which, excluding the 39 MissingNo., leaves 66 different values for other glitch Pokémon.
• In Generation I, a large number (43) of glitch Pokémon have the small katakana character ゥ u in their names. This is because it corresponds to a common codepoint in Game Boy assembly code.
  • The only other Japanese character that appears somewhat frequently in glitch Pokémon's names is small ァ a. The hiragana ぉ o and ぇ e also appear, but less often.
    • The reason for any Japanese text in an English game can be seen here.
• 23' 0"/880.6 lbs. are the most common height and weight values for Red and Blue glitch Pokémon, and 23' 2"/1031.6 lbs. for Yellow. It is unknown as to why any glitch Pokémon have the same values, however.
• Some glitch Pokémon have four or more evolutionary stages, more than any valid Pokémon.
• Encountering a MissingNo., or a few other glitch Pokémon, will cause the screen to go blank for a small amount of time before the battle begins.
  • The same also occurs when they are sent out in battle, but the game will buffer on the battle screen rather than a black screen.
  • Glitch screens also sometimes appear while the game is waiting to send the Pokémon out.

References

Glitches in the Pokémon games Multiple generations Transform glitches • Glitch Trainers • Cloning glitches • Error messages • Arbitrary code execution Generation I Glitches • Battle glitches • Overworld glitches -- • 0 ERROR • Broken hidden items • Cable Club escape glitch • Dual-type damage misinformation Experience underflow glitch • Fight Safari Zone Pokémon trick • Glitch City • Item duplication glitch • Item underflow Mew glitch • Old man glitch • Pewter Gym skip glitch • Pokémon merge glitch • Rhydon glitch • Rival twins glitch Select glitches (dokokashira door glitch, second type glitch) • Super Glitch Time Capsule exploit • Walking through walls • ZZAZZ glitch Generation II Glitches • Battle glitches Bug-Catching Contest glitch • Celebi Egg glitch • Coin Case glitches • Experience underflow glitch Glitch dimension • Glitch Egg • Teru-sama • Time Capsule exploit • Trainer House glitches • GS Ball mail glitch Generation III Glitches • Battle glitches • Overworld glitches Berry glitch • Dive glitch • Pomeg glitch • Glitzer Popping Generation IV Glitches • Battle glitches • Overworld glitches Acid rain • GTS glitches • Pomeg glitch • Rage glitch Surf glitch • Tweaking • Pal Park Retire glitch Generation V Glitches • Battle glitches • Overworld glitches Charge Beam additional effect chance glitch • Charge move replacement glitch • Choice item lock glitch Frozen Zoroark glitch • Sky Drop glitch Generation VI Glitches • Battle glitches • Overworld glitches Charge Beam additional effect chance glitch • Charge move replacement glitch • Choice item lock glitch Lumiose City save glitch • Symbiosis Eject Button glitch • Toxic sure-hit glitch Generation VII Glitches • Battle glitches Charge Beam additional effect chance glitch • Charge move replacement glitch • Choice item lock glitch Toxic sure-hit glitch • Rollout storage glitch Generation VIII Glitches Charge Beam additional effect chance glitch • Charge move replacement glitch • Choice item lock glitch Toxic sure-hit glitch • Rollout storage glitch • Party item offset glitch Generation IX Glitches Glitch effects Game freeze • Glitch battle • Glitch song Gen I only: Glitch screen • TMTRAINER effect • Inverted sprite Gen II only: Glitch dimension Lists Glitches (GO • Mystery Dungeon • TCG GB • Spin-off) Glitch Pokémon (Gen I • Gen II • Gen III • Gen IV • Gen V • Gen VI • Gen VII • Gen VIII) Glitch moves (Gen I) • Glitch types (Gen I • Gen II)

Glitch Pokémon Red/Blue: 'M (00) • MissingNo. • ▶ A • a • ゥ (C1) • ゥ .4 • h POKé PokéWTrainer • PkMn (C5) • ゥL ゥM 4 • ♀Pゥ ゥゥT • ゥU? • ◣ゥ 8 • PC4SH P • PkMn ◣ n • Trainer • ▼ W G d • OPkMn4X • PkMn PkMn T • 4B 8 4 8 ゥ ' • M p'u ゥ • Aゥ G • Pゥ ゥ ゥ • 4 h • Glitch (D7) • PkMnaPkMnゥ ♂ fPkMnk PkMnRPkMn " • B (DA) • Glitch (DB) • Glitch (DC) • 7PkMn 'v • -PkMn • .PkMn /PkMn ▼PkMn • 'v • …… • ゥ (E3) • Glitch (E4) • C • - - Pゥ 4$ • X C • c • A (EA) • Glitch (EB) • Glitch (EC) • hゥ .g • ゥ$'M • ゥ$ (F0) • 94 • ゥ l (F2) • ゥ l (F3) • ゥ$ (F4) ゥ (F5) • G'Mp • 'Ng'Mp • 'Ng ゥ$ • 94 h • Glitch (FA) • 'M 'N g • O ゥ$ 6ゥ • 'M (FE) • 'M (FF) Yellow: 3TrainerPoké $ • MissingNo. • 4 4 • 4 4 Hy • ♀ . • pPkMnp' ' • ゥ ( Z4 X ゥ- xゥ, • 4. . • ァ7g • u • g g • ァ / g J 1 • Glitch (CA) . pゥ • .8 • ゥ. B • PkMn pゥぁ ゥぇ (CE) • 4, ゥァ (CF) • ゥ' • B ァ h PkMn ? A • ゥゥ) • ゥ (D4) • 'ゥ. • PkMn pゥぁ ゥぇ (D6) • B (D7) • PkMn (D8) ゥ (D9) • ] • ゥ' B • PkMn (DC) • 4, ゥァ (DD) • 8 (DE) • p ID 8 P ァ • 'r 'r 4 • (h4to89 • 4 89 4 • 8B 4 8 • Z ゥ • 9 ゥHIゥ. • 4(h4hi?$ • 4HI? • 'r ゥ • $ Pゥ. 4( • ?/ • 4(h4? ゥ► ゥ▼ ゥ • h 4Pゥ ゥ... • . ゥ ( .I' . • ' B' ゥ • ゥ ゥェ ゥ ▷ • ゥ $ A (F3) • ♂ p ゥ ▼ pゥ • ゥ $ A (F6) • PkMn (F7) • ゥ 4- 4 • $ • ゥ▾ ゥ♂ • F q , ゥ$ 4MN ゥ • × 'rゥ. 4- • ゥ/ 4ァ 4, • Q ◣ Generation II: ????? (00GS • FCGS • FEGS • FFGS • 00C • FCC • FEC • FFC) Glitch Egg • Glitch Unown Generation III: - • ?????????? • ? • Bad Egg Generation IV: ----- • Bad Egg • Generation IV hybrid Generation V: ----- • Bad Egg • Glitch Unown Generation VI: Bad Egg • Generation VI 724+ glitch Pokémon

This article is part of Project GlitchDex, a Bulbapedia project that aims to write comprehensive articles on glitches in the Pokémon games.