feed it the cube things in D&P they are called poffins. and battle with them
Make the Chansey Max Happy then level it up.
Go l the day care (make sure you have a crestella first XD) and put it in there with a Pokemon with the same nature. They may or may not have little babies. If they don't find another Pokemon that might make crestella happy.
You can make it happy by treating it to spa.
No, Leafeon is a 4th Generation Pokemon, and thus was not programmed into Pokemon XD. The only Pokemon of future generations to make an appearance are Munchlax and Bonsly.
one word, chocolate. XD
There is no under in Pokemon Xd, there is in Pokemon Colosseum
You can make it happy by training it a whole lot. usually it takes a Pokemon 20-30 LVs to be fully happy.
Pokemon xd in my opinion
Pokemon XD is a Pokemon game for Nintendo GameCube.
You cant actually CATCH electabuzz in Pokemon sapphire/emerald/ruby, but u can trade electabuzz from fire red, and Pokemon XD. happy to help
you have to run around with it lots. also battle with it. those two things make Pokemon happy.
You cannot snag a legit whismur in Pokemon XD, only trade to Pokemon XD from another game.