Watford fans – poke, prod and taunt him if you dare. You won't like David Nugent when he's angry.
Just ask Norwich, Millwall, Leeds, Barnsley, Hull, Middlesbrough, Leicester and Crystal Palace.
The Pompey striker may seem an affable, easy-going sort of chap with a broad smile tattooed on his face.
But, as opposition fans have found to their cost this season, beneath that amiable exterior is a hornet's nest.
And woe betide any football fan wishing to disturb it with poison-tipped barbs from the stands.
One family from Norwich will testify to that.
Their decision to target Nugent for abuse during the recent Carrow Road encounter sparked an explosive backlash from the 25-year-old.
He proceeded to tear the high-flying Canaries apart, creating both of Pompey's goals in the 2-0 triumph.
Since then, Nugent has maintained his form with goals against Millwall and Leeds over the Christmas period.
The former Preston man now has seven goals in his past 13 matches.
Next up are Watford tomorrow – a clash which will see more responsibility than ever heaped on Nugent's shoulders with Dave Kitson suspended.
And any banter aimed in his direction from the home faithful would be rather ill-advised.
Nugent said: 'At Norwich, there was a family at the start of the game giving me a bit of stick, telling me I was rubbish.
'So I thought I'd put on a bit of a show for them. During the game I was giving him a little bit and he didn't know what to say. It was all good.
'I didn't mean to offend them that much – I was getting pound coins thrown at my head, which wasn't nice.
'But I enjoyed it – it was sweet.
'It's especially good when the fans are telling you that you're rubbish.
'It shows they are fearful of you and know you are a good player.
'So the more rubbish I get thrown at me the better I'll play, probably.
'I love winning football games.
'I've not had many over my time at Burnley (where Nugent was on loan last season).
'We seemed to lose every week in the Premier League so it's nice to win games and show it to the fans.
'They've travelled a long way to see games and it is only right to pay them back at the end.'
Pompey head to Watford looking to extend their unbeaten away run to four matches.
Impressive victories at Swansea and Norwich were followed by the dramatic 3-3 draw at Leeds on Tuesday.
Hopes, however, have received a blow with the news boss Steve Cotterill is without a string of players through either injury, suspension or contractual issues.
The Blues already have the smallest squad in the entire Football League.
And Nugent believes it is vital it is strengthened when the transfer window opens tomorrow. He added: 'We can't even fill the bench at the moment.
'We're waiting for January to come around and hopefully get a few more players in there and make the squad stronger.
'You look at the talent in our squad, you look at our starting XI and it is probably one of the strongest in the league. Recently, we have shown we are capable of that.
'We are playing well at the moment and we need to keep it going.
'The start of the season wasn't the best – no wins in seven and we all thought "here we go again".
'But we picked up, went on a great run of form and are now back to our best and showing it on the pitch.'