Where do you get swinub on Pokemon diamond?
Once you have the national pokedex go to lucas's sister (Dawn's sister if you play as a boy) in sandgem tow. Every now and again she will say that there are lots of swinub near snowpoint city! Fly there run around in the grass until you find one. It will evolve into piloswine (I don't know how) and then a mamoswine by learning achient power!
:) Good luck :)