At one time during my Boy Scout career I was patrol leader of the Tiger Patrol. As a joke I started encouraging or just cheering up the other guys by saying, "We're grrrreat!" And they started doing it too. Our voices were always loaded with sarcasm, but there was a deep sincerity. It was one of the few brief periods when everybody got along, everybody had a good time, and no one cared if we didn't place in any of the camporee competitions. Tasked with tying a giant clove hitch around a tree it didn't matter if half of us didn't know how to tie a clove hitch.
I'm afraid that was a few years before Mr. Marshall's time, but it doesn't matter. I have a special fondness for Tony The Tiger, whoever he may be.