It's certainly not an Irish song, Angus Og (young Angus) brought his Donalds from Islay to fight alongside The Bruce at Bannockburn.

The song however relates to the Daily Record cartoon character by Ewan Bain who I believe was from Skye, was sung by Alistair Gillies and goes along the lines of:

Many battle's there have been
Many hero's we have seen
Who have risen up in answer to the call
Bruce and Wallace and the rest
Put the English to the test
But I'll tell you of the greatest hero
Of them all

He's a wily highland man
Making money while he can
And his antics are the talk of all the folk
Through his wee bit but'n'ben
Come the English gentlemen
And they don't get out again
Until their stoney broke

Angus Og, Angus Og
He's a devil he's a rascal he's a rogue
From John o'Groats to Skye
Edinburgh to Milngavie
There is no-one who is half as fly as Angus Og

Now in the Outer Hebrides
The board gave Angus subsidies
So he built a rocket pointing to the sky
Marileen and Lachie Mhor uploaded bottles by the score
Since Angus first discovered that the moon was dry

Ach said angus very soon
I'll have a pub up in the moon
and I'm going to make a fortune so I am
for when the human race starts to travel into space
I'll have the only place where they can have a Dram

Angus Og, Angus Og
He's a devil he's a rascal he's a rogue
From John o'Groats to Skye
Edinburgh to Milngavie
There is no-one who is half as fly as Angus Og

Well he borrowed Lachie's car
And he covered it in tar
Then he stuck a jet propeller on it's tail
He put some whisky in the tank and the rest of it he drank
The he took it to Loch Oovie for its maiden sail
Well you've never saw such power it did ninety miles an hour
But it sank before it got halfway across
Ach said Angus what a boat, perhaps it didnae float
But it's the fastest little submarine there ever was!


Angus Og, Angus Og
He's a devil he's a rascal he's a rogue
From John o'Groats to Skye
Edinburgh to Milngavie
There is no-one who is half as fly as Angus Og
There is no-one who is half as fly as Angus Og

Angus Og, Angus Og
He's a devil he's a rascal he's a rogue
From John o'Groats to Skye
Edinburgh to Milngavie
There is no-one who is half as fly as Angus Og