Green’s Dictionary of Slang

1. a shabby beggar.

1812		Vaux Vocab. of the Flash Lang. in McLachlan (1964) 254: needy-mizzler a poor ragged object of either sex; a shabby-looking person.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1834		(con. 1737–9) W.H. Ainsworth Rookwood (1857) 168: A needy mizzler myself.
1840		T. Haliburton Letter-bag of the Great Western (1873) 105: I don’t mene this by way of discouragement, but to int you are too fond of drink, and keeping company with needy mizlers.
1856		‘A Harassing Painsworth’ in Yates & Brough (eds) Our Miscellany 28: Listen! all you high pads and low pads, rum gills and queer gills, patricos, palliards, priggers, whipjacks, and jackmen, from the arch rogue to the needy mizzler.
1868		‘Six Years in the Prisons of England’ in Temple Bar Mag. Nov. 536: Needy mizzlers, mumpers, shallow-blokes, and flats may carry it on.
1870		Hotten Sl. Dict.
1873		Sl. Dict.

2. a tramp who leaves without paying for his lodging.

1864, 1867, 1870		Hotten Sl. Dict.
1873		Sl. Dict.
1882		Sydney Sl. Dict. (2 edn) 6: Needy Mizzler - A shabby person; a tramp who runs away without paying for his lodging.
1895		C. Crowe Aus. Sl. Dict. [as 1882].

3. anyone on the street without a home.

1886

Reynold’s Newspaper (London) 12 Dec. 2/2: It’s a cold night for such a needy mizzler to take a diver.