Pikachu came in 18th and 19th Generaton Hang Tags,  and the single, not looped, 15th Generaton Tush Tag. It was introduced in October 2011. (00 in date means no specific day)

Ty released six Pokemon characters at the same time Tepig, Pikachu, Axew, Pansage, Oshawott, Snivy

Tush tag: Pikachu

See other Pokemon characters.