It wasn't much of a joke.
At sixteen or seventeen the teller was six foot four, athletic, a hunter, camper and martial artist, and by his own admission a cocky teenager who thought he was invincible. He was on a summer holiday with his cousin and grandparents at the family cabin on Long Lake near Danbury, in the forests of northwestern Wisconsin.
On a hot afternoon the two cousins played airsoft. The teller took it seriously: full woodland camouflage and a mask. His cousin wore jeans and a T-shirt. The teller led the game into the woods, where he felt at home, and about 150 metres in they stopped. To tease his cousin, he shushed him and whispered that they were being watched.
It turned out not to be much of a joke. As soon as he said it, he noticed that the woods had gone dead silent, which in his experience means a big predator is near. Then the feeling of being watched hit him for real. He started scanning the trees, and what gave it away was a glint of whitish teeth.
At the edge of a clearing about forty metres away, something was crouched, holding a tree with its left hand. It was panting and watching them with its ears up. It had reddish-brown fur and a canine look. The word that clicked in his head was werewolf.
He told his cousin they had to go, and the cousin bolted. The teller still had his eyes on it when his cousin started running, and in that instant it charged. It ran on two legs for perhaps ten feet, then dropped to all fours. The teller turned and sprinted. All the way out of the woods he could hear it crashing through the undergrowth behind them.
Back at the cabin he told his cousin it must have been a bear, so as not to frighten him. He's still not sure whether his cousin actually saw it. He knows bears, and it wasn't one. Researching afterward, he found that what he'd seen matched other people's dogman sightings. He later told his story on a radio programme devoted to them.
He says it humbled him. He's careful in the woods now, always armed when he goes alone, and prefers not to go alone at all. His advice: always trust your senses.