Bow To Your Master:

In the beginning, go to Pikachu's discovery days. Go to any level and say "FIERCE DIETY" (DEE-I-TEE). He will start to bow down at you!

Another Cheat:

At any level, say "orochi" (OR-O-CHEE). He will start thunderbolting like crazy! You may have to complete the game to do this first. to complete it, catch all of the best, water all the oddish, that sort of thing.

Toge-pi:

Go to The Orchre Picnic game and go to the section on the very right. You will find a cave. Say "cave" to Pikachu and he will come out with a Togepi Egg. Abra will fall out of the sky.He will take the egg. Visit the shop often enough to hatch the egg. If Pikachu had bought a balloon the time Togepi hatches, he will give the baloon to Togepi!

Secret Camp-out:

Beat the Pinata stage with Venusaur perfectly and you shall be taken to a hidden stage. The stage is an overnight campout with Pikachu. Haunter shall sneak up on Pikachu and scare him occasionally.