Who said "Ruh-roh! When Scooby gets scared, you know it's serious."?

This quote is attributed to Scooby-Doo.

Ruh-roh! When Scooby gets scared, you know it's serious. - Scooby-Doo

"Ruh-roh! When Scooby gets scared, you know it's serious."

Scooby-Doo Fear

"Scooby-Dooby-Doo, where are you?"

"Ruh-roh!"

"Like, zoinks!"

"Let's split up, gang!"

"Face your fears with courage."

"You can't live your life in fear."

"Snakes. Why'd it have to be snakes?"

"Fear is just another obstacle to overcome."