Plenty of hardmen/nutters mentioned but, as with lots of lists, most of the players mentioned so far are from the upper echelons of football. Here are a few that I can recall from a bit lower down the pecking order.

Eric Winstanley
It always seemed that the City never got much change out of Duncan Forbes and David Stringer of Norwich
Walter Bingley
Mark Dennis
I remember it being said in the Press that just saying the names of the Middlesbrough defence of the early 70s was like chewing iron filings- Frank Spraggon, John Craggs, Stuart Boam, Willie Maddren - a formidable lot when they were Div 2 Champions
Eric Skeels
Harry Cripps
Roger Hynd
Ian Ure was a fearsome centre half for Arsenal and, in the 3rd round FA cup tie v Arsenal in 1969, John Toshack got absolutely nowhere against him

I'm sure that there are plenty of others from the lower divisions that posters will recall