Funnily enough i have seen one whilst out with a hunt terrierman and other mate near cheltenham a few years back, it came through 20mins before the hounds Went past a 6bar gate so the 3 of us all saw the size of it (all turned to each other and said did you see that!) the hounds took the same trail showing a size comparison, it was fookin massive compared to them!!
Have also seen pug marks in the mud on farmland in wiltshire, big with no claw marks so not dog tracks!
Don't forget they can shin up a tree in seconds and you may well walk right on past without ever even knowing it was there!