A derogatory name for French soldiers (or indeed the French as a whole).

The Monsewers sent us our breakfast - an appetiser of shrapnel, followed by a main course of countless shells.

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Note added at 6 hrs (2014-01-15 17:27:16 GMT)
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In WWII the expressions Franzmänner (Germany) and Frogs (Britain) would have been more likely.

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Note added at 11 hrs (2014-01-15 22:07:45 GMT)
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WW I and earlier, the German term was the term most likely to be (in its friendliest form)
"Der Franzos". Frog, frogs, froggies is typical WW II.

I know my dad called them frogs (and Vichy bastards!) when his unit helped the Free French to kick them out of Aleppo in Syria in the summer of 1941 (yes, the Brits fought against the French in WW II!) and later in Algeria and Tunisia.

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Note added at 11 hrs (2014-01-15 22:26:19 GMT)
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A bit of trivia:
Since the 18th century, the name “John Bull,” according to the OED, has personified “the English nation; Englishmen collectively; the typical Englishman.”

Early in the following century, the name “Johnny (or Jean) Crapaud” was first used to mean a Frenchman, Oxford says. (Crapaud is French for “toad.”)

Could this be what developed into frog? The most effective weapon of the French army in WW I was also called a Crapaud, a squat trench mortar.

More trivia: servicemens' nicknames for themselves and others:
ANZACs: Australians and New Zealanders (from A. and NZ. Army Corps).
Americans: Yanks. For themselves = Doughboys. French version = Sammy. German version = Teufelshunde (Devil dogs, for US Marines)
Australians: Aussie, Digger. For themselves = Billjim, Dinkum (for Australian Gallipoli veteran), Tazzie (from Tazmania), Westralian (from Western Australia).
British: Tommy, (also used by the Germans), Tommy Atkins, Fred Karno's Army, Old Contemptibles. Also Jock = Scotsman, Mick = Irishman. Australian version = Kitch = (Kitchener's Volunteer Army).
Canadians: Canuck.
Egyptians: Gyppo.
French: Frenchie, Frog. For themselves = Bon hommes (gentlemen) and Poilus (bearded ones).
Germans: Alleyman, Boche, Hun, Jerry, Kraut (from Sauerkraut), and Square head (after the shape of the STAHLHELM M1916 steel helmet). American version = Heine. For themselves = Frontschwein (Front-line pigs)
Italians: Macaroni, Itie.
New Zealanders: Digger, Kiwi, Fern-leaf (after the NZ cap-badge), Enzedder.
Ottomans/Turks: Abdul, Jacko, Johnny Turk.
Pathans: Forty Thieves. (Indian troops from the North West Frontier Province, now Pakistan).
Portuguese: Antonio, Geese, Pork and beans, Pork and cheese.
Russians: Russkie.
South Africans: Afrikaaner, Boer.