In the National Dex.
You are able to obtain dialgas' picture after you encounter it
you can't catch dialgas anywere
Hayley does not bring any Dialgas to your ranch, so the only way to get a Dialga would be to trade from Diamond, Pearl or Platinum.
palkia
Buy a action replay for $20 and look up how to get all legendarys again then put it L+R and do it when walking in and they both are there.I have Pokemon Pearl and got 800 of both.Its awesome.
Dialga has no evolution stage.
you cant
Yes but only if you trade or have an AR.
You canot a dialga egg in pokemon black and white.
No. And it wasn't nominated for Best Picture.
you cant
When you see Dialga. Look around (I think its south) You'll find it.