Celebi

Celebi (セレビィ, Serebī, Cerebi in Japanese language versions) is a fictional creature in the Pokémon media franchise.

Creature description
Celebi is known as the Time Travelling Pokémon, and is #251 on the Pokédex. It is the "secret rare" Pokémon of the Second Generation, just as Mew was in the First. It is a green, insect-like sprite with great power and ability.

As a Poké Ball Pokémon
Celebi is very special among summonable Pokémon. First of all, it must be unlocked; it won't appear out of a Poké Ball until all playable characters and stages have been unlocked, the sound test has been unlocked, and all Event Matches have been completed. Once that's done, the chance of Celebi appearing is 1-251 ("251" being the total number of Pokémon in existence at the time of Melee's release), just like the other "unlockable" Pokémon, Mew. (Both have a double-chance of appearing in Event 37: Legendary Pokémon, though.)

Like Mew, Celebi's action is not an attack; Celebi gently flies off the screen a few seconds after it's summoned. The point of the summon is that the summoner is awarded the rare Celebi Catcher bonus for 8,000 Points; the first time this is achieved it yields a Special achievement message and earns you the Celebi trophy.

As a trophy
Celebi, as with all other Poké Ball Pokémon, features as a collectible trophy; this trophy must be specifically earned by encountering Celebi once during any match. This makes it one of the hardest trophies to earn, because you must essentially play the entire game through before the 1-251 chance of Celebi appearing in a Poké Ball is put into effect, and that is a very rare occurence indeed; throwing 251 separate Poké Balls does not guarantee one appearance by Celebi among them. Its description reads as follows:


 * Celebi
 * (Input Trophy description here)