Moyes has been the butt of all jokes on the internet, but this anonymous fan certainly isn't laughing as he got the permanent mark on his own bottom.
Under Moyes, United have gone from champions to a lowly seventh in the table and are already out of the FA Cup and League Cup. Their final chance at a trophy, the Champions League, looks an increasingly unlikely possibility too after they lost 2-0 to Olympiacos in the first leg of their Champions League last 16 tie on Tuesday.
Of course, if Moyes does what Sir Alex Ferguson did at United and turns the club around after a slow start, then this fan is going to look like even more of an idiot than he does already.
We have been here with football fans before after all...
Back in 2009, a Manchester City fan was left embarrassed after having 'Kaka' tattooed on his chest before the AC Milan star snubbed the club in favour of a move to Real Madrid. He then decided to get a Robinho tattoo which didn't work out too well either.
There must have been something in the Manchester water back in 2009 because another City fan got a tattoo saying "Manchester City – 2011 Champions League winners" with a picture of the European Cup when the club did not even qualify for the competition that season.
While just last September, a Liverpool fan got a tattoo of Kolo Toure’s name on his foot (a questionable move in the first place), only to then later realise the tattoo artist spelt the player's name 'Kolo Touro.'
So kids, if you really must get the a tattoo, how about getting something like 'mum' or a nice barbed-wire ring instead, eh?