My first girlfriend had an uncle well know in south London, he was refered to with the word 'Tiger' before his name.
He was probably in his late 60's when I knew him and had an adult disabled son he took care of.
I heard a story from around this time when once he got on a train with his son, his son sat between two black guys who proceded to take the piss out of him.
Apparently he beat the living daylights out of the pair of them, he was quiet,no taller than 5' 7" and slightly built.