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