The version that I learnt is a call and response thing. I learnt it when I was leading on a children's camp, and the children were big fans of it. The lyrics are as follows:
My Highland Goat (Not a chicken, but a Goat)
Was feeling fine, (Not well, but fine)
Eat 16 shirts, (Not skirts but shirts)
From off the line, (Not a circle, but a line)
My master, Mack, (Not Jack, but Mack)
Gave him a smack (Not a whack, but a smack)
And tied him to, (Not from, but to)
The railway track, (Not a line, but a track)
The whistle blew (Not red but blew)
The train drew neigh, (Not far, but neigh)
My Highland Goat (Not a chicken, but a goat)
Was sure to die, (Not live, but die)
He gave a cry (Not a wail, but a cry)
Of mortal pain, (Not pleasure, but pain)
Coughed up the shirts, (Not skirts but shirts)
Flagged down the train! (Not a plane but a train!)