A variation on one of Bob Bolton's:

A Texan cattle rancher visits Australia to see for himself the way they do it, and is not impressed. He starts bragging to a Station Manager.

"How big is this place?"

"Dunno, about a couple of thousand square miles, I reckon."

"Well, my spread in Texas is at least twice that. How many head of cattle do you have?"

"Can't say, I don't bother counting them all. Mebbe twenty thousand."

"My herd in Texas is at least twice that. I tell you boy, everything in Texas is twice as big as it is here"

At this point a kangaroo bounds past

"What the!?", shouts the Texan. "What in the name of Jesus H. Christ and General Patton was that?"

"That?", says the Australian. "That's a rabbit, mate. They can get to be quite a big pest round here. Don't you get rabbits in Texas?"