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The Celebi egg trick is a method to obtain Celebi in Gold, Silver, and Crystal. Due to the fact that it is impossible to obtain Celebi via standard gameplay, this is, currently, the only way to get Celebi in the Generation II games without a Nintendo event or using cheat codes. However, like most other glitches, it may damage the player's save data.
This glitch was first documented at Glitch City Laboratories. It was found by Paco81. There is another way to get Celebi; the "Celebi trick" (also found by Paco81), but these two glitches are slightly different.
This is only one known method of carrying out the Celebi egg trick and successfully obtaining the Celebi.
- The egg - The player must get an egg that will know Beat Up as its third move upon hatching. This can be done by training a male and a female Sneasel up to level 57. Both Sneasel need to have the same four moves in the same order, with Beat Up at position three. Because both parents have the same moveset, the offspring will share this moveset.
- The bad clone - The player must get a bad clone, a clone with a name made of only question marks, its level will be 0 and its gender will be different of the prototype's. If that Pokémon doesn't fulfill all those requirements, then it isn't a "bad clone" and it cannot be used for the trick. This can be done by Pokémon cloning. The box that is used for cloning must not be totally filled up at any time (otherwise the box is unable to produce bad clones). Getting a bad clone is a case of luck and occurs sometimes during the act of cloning. The chance of getting a bad clone is at maximum if the box has 15 to 18 Pokémon.
- Last requirement - The player must get any five Pokémon (preferably weak, common or otherwise useless Pokémon). The easiest way to get them is to clone a Pokémon until there is a bad clone. Because getting a bad clone takes some tries, he or she will get five unimportant Pokémon as a positive side effect of the bad clone action.
- Step 1 - The player must first deposit the egg into a box. The five other Pokémon and the bad clone have to be in the party.
- Step 2 - The player must then go to the daycare and ask the man to raise the bad clone. He or she should then take it back from him, and it will be a ?????.
- Step 3 - Next, the player must put ????? at the top of his or her party and go to the PC.
- Step 4 - Using the "Move Pokémon without mail" option, the player must move any Pokémon (preferably weak or common Pokémon) from a PC box to the top of their party. Its name should become the name of its original Trainer. The player will now have 7 Pokémon in his or her party.
- Step 5 - Next, the player must go back to the Daycare man and ask him to raise the ?????. Afterward, he or she should return to the PC.
- Step 6 - Back at the PC, the player must deposit the first and second party Pokémon.
- Step 7 - Using the "Move Pokémon without mail" option, the player must move the egg from its PC box to the top of his or her party.
- Step 8 - Next, the player needs to deposit the next four party Pokémon, but not the egg.
- Step 9 - Subsequently, the player should withdraw any Pokémon that he or she didn't use for the trick.
- Step 10 - Having completed the set up, the player should walk or bike around until the egg hatches into a Celebi. However, the Celebi is still unplayable.
- Step 11- The Celebi will hatch at level 0. Due to how the game handles Pokémon that level up in battle, the player must allow the daycare couple to raise the Celebi to at least level 2. After this, it works like any normal Celebi.
The reason why the player gets Celebi is the Beat Up move. In Generation II, both Celebi and Beat Up share the same index number: 251. This is not random, and should work with any other move-Pokémon combination; Psychic, whose index number is 94, should result in a Gengar hatching, while Splash, despite being the worst move, ironically would bring about a Mewtwo, as both share index number 150. This glitch therefore should not cause any glitch Pokémon to appear, as there were exactly 251 moves in Generation II, though Ledyba would not be obtainable in this way, as Struggle is unobtainable normally as a move.
If the Pokémon used for the breeding has no third attack, the Pokémon that will come out from the egg (after the glitch) will be a "bad clone" of the glitch Pokémon #000 ?????. This Pokémon, like other "bad clones" cannot be seen by the PC, and hence cannot be deposited in the player's PC or released. The only way to release this Pokémon is to trade it to a Generation I game. Upon arrival, it will become a generation I original or glitch Pokémon, which may be released normally.
If a wild Ditto transforms into the hatched ?????, the wild Ditto is no longer catchable by any kind of Poké Ball. Even a Master Ball will fail to capture it. If a Ditto is bred with the "bad clone" of ?????, the offspring will be another "bad clone", knowing only Transform.
The "bad clone" of ????? may evolve to a Nidoran♂. Possible levels for evolution are 62 and 37.
At Step 5 of the trick the player asks a Daycare person to raise the Bad Clone of ????? (000). That clone will not be taken back until the trick is finished. After the trick is finished, that clone will disappear from the Daycare, but in rare occasions it is possible for that Pokémon to not disappear and remain at the Daycare. In that case the Bad Clone of ????? (000) will be transformed into a Bad Clone of ????? (255). That Bad Clone of ????? (255), as the Bad Clone of ????? (000), cannot be released by the PC, but it still can be traded to a generation I game and released there. But it has some differences with the Bad Clone of ????? (000), as it cannot evolve into a Nidoran♂, and a wild Ditto transforms into the hatched ????? (255), the wild Ditto can be caught normally.
The hatched Pokémon's item
The hatched Pokémon will hold an item depending to the fourth attack of the Pokémon used for the breeding. Both the item and the fourth attack share the same index number. For example, if the two Pokémon (used for the breeding) have as fourth attack the move Reflect, the hatched Pokémon will hold a GS Ball. That's because both GS Ball and Reflect have the same index number: 115. If the Pokémon used for the breeding have as fourth attack the move Whirlpool or Beat Up, the hatched Pokémon will hold the item HM08 or HM09 respectively. If the Pokémon used for the breeding has no fourth attack, the hatched Pokémon will hold nothing.
Some of the Pokémon that are deposited in step 6 and step 8 may have their names, gender, level, or attacks changed. Some of them will become "bad clones" and some will remain normal Pokémon. Some of them will have also the Pokérus virus.
*Indicates glitches which have been officially acknowledged