Who said "Loyalty is the mark of true friendship."?

This quote is attributed to Pikachu.

Loyalty is the mark of true friendship. - Pikachu

"Loyalty is the mark of true friendship."

Pikachu Friendship

"Pika pika!"

"Pikachu!"

"Pika pika chu!"

"I choose you!"

"Friendship is built on trust and honesty."

"True friendship is worth more than gold."

"Good friends are like stars, always there even when you can't see them."

"Friendship means sacrifice."