An alcoholic (euphemism). Used by local newspapers when reporting the death of winos. Usually a "character" is of no fixed abode, or at least of very limited means.
Respectable dead alcoholics, by contrast, are merely "convivial"; even if they are crazed ranters they would be "convivial and garrulous".
"Mr Brew was a popular local character, normally to be found by the war memorial in the high street".