you catch him on the cave
you do not find dialga in Pokemon pearl
we find dialga in map 3 in Pokemon deluge...
you can find dialga in map 16 you can also find arceus in map 16 too
spear pillar
Dialga is not in that Pokemon Emerald. Back when that game was made, Dialga didn't exist.
in your house
You can get dialga in cluod map
you do not find dialga in Pokemon pearl
You must get past Dialga and Palkia and have cresselia unlocked to enter dark crater
we find dialga in map 3 in Pokemon deluge...
you find dialga in mount coronet
you pee on him
you dont
go on Pokemon crater
Trade with Pokemon Pearl or Pokemon Platinum
I don't think Dialga can be hatched from an egg. You can find Dialga at Spear Pillar though.
you can find dialga in map 16 you can also find arceus in map 16 too