you can go get him. At the trohpy garrden next to hearthome city
Pichu evolves by happiness.
That Pokemon is pichu.
you get it at trophy garden
in mrs bachlot mansion
Pichu will only evolve when it has max happiness with its trainer.
The next Mystery gift is for Diamond Pearl and Platnium march the 5-25 you get a Pikachu coloured pichu(shiny pichu). It might not seem much but if you trade it to HeartGold or SoulSilver it unlocks the spiky eared pichu
Wild Pichu can be found in the Trophy Garden, which is a bit under Hearthome city in Diamond/Pearl/Platinum.
not hard
in pokemon pearl/diamond it is in the trophy garden
when it has high friendship
you can get it at the trophy garden
Breed it with a Voltorb