Seen and *ahem* touched one on the WHW last year about half a mile before Beinglas campsite. There was a group of 4 of us, 2 girls were 100 meters or so ahead of us and then my mate passed it before me. Not a single one spotted it, then muggins here seen it from about a foot away as I was about to stand on it. it was about a foot long and twice as thick as a pencil. seeing as it hadn't moved (and I knew hee haw about snakes) I thought it was dead. wasn't until I called my mate back and we both discussed about it, I toe tapped it, for it to wriggle off into the underbrush at some speed and leaving me needing a kit change. Naturally you research these things afterwards and discover it was sunning it's self on the stones
Obviously by the time we sat around a meal in Bein Glas after pitching the tents and having a shower, the story had evolved from a toe tap and a kit change to it attacked me and got booted to it's senses. Alcohol may have been involved.
*no snakes were hurt during this event*