My mother taught me Paddy McGinty's goat when I was a child. She said that her younger brother had taught it to her when she was a child. There are at least two WWI verses that I know. The first one is:

Off the west coast of Ireland, one morning there was seen
As sure as a pipestack, a German submarine
The coast guard Mahoney, fell over in a fit
Twas up to Paddy McGinty's goat to do his very bit
He dived in the water as frisky as a whale
He swam around the U boat and wagged his little tail
Then up with his horns and he got 'em in the bow
and sent the Huns to hell-a-go land, did Paddy McGinty's goat

The second WWI verse is:

The brave Irish lads, the ones that like to dance
Adoopted the goat and took him off to France
The day that they landed, they heard the bugle blow
He ducked his little cranium and ran to meet the foe
The Germans retreated and hurridly they spread
All holding their noses, they stumbled over dead
"Ach" said the Kaiser "There's poison gas afloat"
But it was just the awful smell of Paddy McGinty's goat