As many of toi probably already know, for a time on your copies of diamond/pearl/platinum toi could have recieved a pichu coloured pichu. If toi did recieve that pichu then toi could get a spiky eared pichu par trading it into a copy of pokemon cœur, coeur gold/soul silver. To do this -
1. First play the game up until after the seconde gym. Trade in your Pikachu coloured pichu and make sure it is first in your party
2. Go left out of Azelea town and into Ilex forest.
3. If toi haven't already then help out the boy and catch the Farfetche'd. He wil give toi the hm cut.
4. Teach the hm to one of your pokemon and cut down the arbre near to where the guy toi helped was standing.
5. Walk up that way and watch the event unfold...
The pichu toi get with this event cannot be evolved however it has some interesting moves that toi wouldn't normally expect a pichu to learn.
If toi accidentally evolved your Pikachu coloured pichu the event will still work.
HAVE FUN! =D