Johnny Foreigner 

1. Anyone who isn't British.
2. Anyone likely to be given a metaphorical 'bloody nose' by a plucky Brit.

Examples include 'Jerry' and 'the Frogs' (in that order)

See also
The Great Escape (1963), in which Johnny Foreigner is given a sound thrashing by a number of plucky Brits and other less important characters from the colonies. Later on, without giving away the plot, events go slightly a wry for the protagonists. Not to worry though, as Jerry's uppence comes, eventually leading to the end of Nazi Germany.

Johnny Foreigner by Sqn Ldr Cavendish-Stockley February 2, 2010

Johnny Foreigner 

A chap who isn't from English i.e. foreigner but to make him sound more un-English add Johnny

Johnny Foreigner: Purpose of visit
Englishman: Imperialism now out of my way Johnny Foreigner
JF: Yes sir, tell me more of these pounds and inches

Johnny Foreigner by Stutley February 1, 2005