I've been trying to find an interview with Mike Myers where he supposedly mentions the inspiration for the Fat Bastard character. My friend swears that Mike Myers said he saw an obese guy in Nashville, TN playing the bagpipes and that was where he got the idea for Fat Bastard. So who is the inspirational character for Fat Bastard?
I cannot find any mention of any interview with Mike Myers where he reveals the inspiration for Fat Bastard. That does not mean that there was none. But I'd like to venture that if such a revelation had ever been made, then it would have been mentioned here, here, here, or here.
My first impression when I saw Fat Bastard (and this opinion is shared in a number of locations) was that he was modelled on the legendary character of Mr. Creosote from Monty Python's The Meaning of Life. Myers grew up with Monty Python and would have undoubtedly encountered the double Jeroboam swilling Creosote.