Where do you go to find the egg of crawdaunt in Pokemon platinum?

You can't get a crawdaunt egg ,but you can migrate a corpish and evolve it at level 30 or you can just migrate a crawdaunt from another game ,but no matter what you can't catch a crawdaunt or make a crawdaunt egg (you might be able to make a crawdaunt egg with the action replay ,but I'm not sure because i don't have one)