Here it is as I learned it about 35 years ago from an Irish singer whose name escapes me (It's an age thing, I know). He accompanied himself on the bodhran, and it added rather than detracted.

There was a little man and he had a little horse
He saddled it and bridled it and got his leg across
Cho : Johnny Rattledum, rattledum, rattledum day
Hi Johnny Rattledum day.

He rode, he rode til he came to a brook
And there he saw a fisherman fishing with a hook. Cho.

O fisherman, O fisherman who I can see
Have you got a crabfish you can sell to me. Cho.

I haven't got a crabfish as you can see
But I has a lobster I will sell to ye. Cho.

He took the lobster home but couldn't find a big enough dish
So they put it in the pot where his missis used to pish. Cho.

In the middle of the night as you might well know
The missis got up to use the Edgar Allan Poe [sic]. Cho.

She said husband, husband, as surely as you're born
The devil's in the pisspot and he's pushing up his horn. Cho.

She gave a screech and she gave a grunt
And ran round the room with the lobster up her nightie. Cho.

He grabbed a shovel and she grabbed a broom
And they hit the fing lobster all around the room. Cho.

They hit him on the head and they hit him on the side
And they hit him up the arse and the poor bugger died. Cho.

The moral of the story goes like this :
Look in the pisspot before you has a piss. Cho.