If I were to breed two pokemon , which two would produce a pichu?
Breed ANY of http://pokemondb.net/mechanics/egg-groups/fairy or these http://pokemondb.net/mechanics/egg-groups/field with a female pikachu or female raichu. Alternatively a male/female pikachu/raichu will work with ditto but a PICHU CANNOT BREED, no Pokemon in this http://pokemondb.net/mechanics/egg-groups/undiscovered group can breed they may need to EVOLVE or they are legendey Pokemon, only 1 legendry can breed, manphy and she makes phione
You can just breed a Pikachu with a Ditto, and the egg will be Pichu.
You can also breed a male Pikachu with a female Pikachu, either way will still get you a Pichu egg.
(+) Raichu works as well. lt does not have to be Pikachu.
You will have to breed a female Raichu, or Pikachu with any other pokemon to get a Pichu egg. ;)
For the ultimate pichu get two raichus/pikachus or one of each and and have the male (which for me was a pikachu) hold an electro ball and with tms have it learn iron tail and dig or another of your choice and have know thunder bolt and put the two in the daycare the resulting pichu will know
this happened for me on hg/ss
hope this helped