Nick's Pokemon Fan Site
Pokemon Master Quest: Hocus Pokemon
This video is also uploaded on You Tube
This is the episode where Ash meets up with a Pokemon Magician and she's asks for Ash's help using Pikachu with a spell that allows people to enter the minds of Pokemon, but she also needs help getting stun spore from a Parasect and a tear from a Aipom. After they get all this Ash trys the spell, but instead Ash entering the mind of his Pikachu he turns into a Pikachu himself!
I've finally found this episode on my video tape after 4 years, this is my favorite Pokemon Master Quest episode =)