Question

What is the secret ID of the Event Pokemon you receive?

Answer 1

Mostly an event Pokemon's Secret ID is simply 00000.
However sometimes it can be an actual secret ID, like the Winter Celebi 2011.

Hope I helped. :)
Source

Comments

Your right but it's five 0's not 6 :P

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Oh, thanks. xD

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No problem :)

Answer 2

I'm not sure if you're asking what the ID's of those Pokemon are or what an ID is in general, but every trainer has an ID and a secret ID, as well as the Pokemon they catch or breed. The secret ID determines if the Pokemon is shiny or not.

>While it is common knowledge that each trainer has an ID, it is somewhat less known that he or she also has a Secret ID which is hidden away. Like the Trainer ID, this Secret ID is also recorded on each Pokemon a Trainer captures or breeds. This Secret ID is used in the equation which determines whether a Pokemon is shiny or not.

Source

Hope I helped.

Answer 3

Different event Pokemon have different secret IDs as listed here.
That link may be old but it shows the secret IDs of some event Pokemon and that they are not the same.

Hope I helped!