You can get any legendary egg by using this actionreplay code all you need to do is get a ditto then put it in the daycare with anything including legendaries.If you want a legendary egg you have to use this code which makes an egg appear no matter what.

It is:94000136 fffe0000
b21c4d28 00000000
b0000004 00000000
e0001860 00000005
a1ba0f8e 00000002
d2000000 00000000 and it will de the ledendary pokemon.If you want the egg to hatch faster use this code:921ed410 00004281
121ed410 00004289
d2000000 00000000