Who said "Standing guard is my purpose."?

This quote is attributed to Knuckles.

Standing guard is my purpose. - Knuckles

"Standing guard is my purpose."

Knuckles

"I'm the last one standing!"

"Gotta protect this Master Emerald!"

"Nobody messes with the Master Emerald while I'm around!"

"I may not be the smartest guy, but I know what's right!"