Green’s Dictionary of Slang

you and whose army? phr.

also you and what army? you and who else?

(usu. teen) a phr. addressed to anyone who is threatening violence.

[US]J.L. Kuethe ‘Johns Hopkins Jargon’ in AS VII:5 338: you and what army? — ‘You are not able to do it alone.’.
[UK]F. Norman Fings II i: Collins I’d do that Meatface if I could lay my hands on him. Paddy You and whose Army!
[US]‘Lou Rand’ Gay Detective (2003) 19: ‘Yeah! You and who else?’ came from one of the belligerents.
[US]Mad mag. Dec. 33: Yeah? Him and what army?
[US]E. Thompson Garden of Sand (1981) 316: ‘I’ll throb his dang knob.’ ‘Yeah? You and whose army?’.
[UK]J. Cameron Hell on Hoe Street 172: ‘Some Pakistan geezer reckons I going to waste him,’ [...] ‘You? You and whose army?’.