As many of Ты probably already know, for a time on your copies of diamond/pearl/platinum Ты could have recieved a pichu coloured pichu. If Ты did recieve that pichu then Ты could get a spiky eared pichu by trading it into a copy of pokemon сердце gold/soul silver. To do this -

1. First play the game up until after the секунда gym. Trade in your Пикачу coloured pichu and make sure it is first in your party
2. Go left out of Azelea town and into Ilex forest.
3. If Ты haven't already then help out the boy and catch the Farfetche'd. He wil give Ты the hm cut.
4. Teach the hm to one of your pokemon and cut down the дерево near to where the guy Ты helped was standing.
5. Walk up that way and watch the event unfold...

The pichu Ты get with this event cannot be evolved however it has some interesting moves that Ты wouldn't normally expect a pichu to learn.

DON'T WORRY!
If Ты accidentally evolved your Пикачу coloured pichu the event will still work.

HAVE FUN! =D