I've seen real Pikachu actually. They're smaller than the tv counter-parts. Mostly found in the mountains of the West Coast. My family calls em Potguts since they're so fat from people feeding em. They really like potato chips.
Real Pikachu don't have electric powers and it's the males who say "Pika!"...it's a territorial call. They're related to rabbits.
Quite common around camp-grounds. Especially in Utah. That's where I've seen em the most.
Here's an image of one:
