"And then a wee while later, the possum climbed up on to the head of the ewe.
"She didn't like that so much, so she shook her head and the possum fell off.
"She started sniffing it, and it just climbed back on."
That happened a couple of times, Davis said.
Now that he had seen it with his own eyes, he believed nothing was impossumible.
"Words fail me.
"It's all very weird.
"Clearly, there's something not quite right with the possum," he said.
"He's quite confused at the moment."
He said it was a young one, and they were known to ride on their mother's back at that age.
"It obviously mistook the ewe for its mother for some reason."