Terry was appearing on Sky One’s A League of Their Own on Thursday night when he was asked what it’s like playing with hardman Diego Costa.
And it was then when he revealed how Costa used to think nothing of getting physical in Chelsea training.
That’s despite Terry labelling him as one of the sport’s Mr Nice Guys.
“Costa has that perception of being arrogant but he’s one of the nicest guys I’ve met in football,” Terry said.
“Honestly, off the field he’s the nicest guy. On the field he’s an absolute animal.
“In training he’d elbow you and look at you and be like ‘what have I done wrong there?’
“Off the field I have to say he’s one of the nicest guys I’ve met.”
Terry was also asked to reveal who the biggest party-goer from his time at Stamford Bridge was.
“We’ve had a few, we’ve had a few,” Terry pondered.
Former Spice Girl Geri Horner then asks if it was Frank Lampard to which he replied: “No not Frank, no. He’s a true professional Lamps. He’s really really fit.
“I would say in my time Deco. Or Mark Bosnich as well.”
Terry earlier revealed why he wore his full Chelsea kit – including a set of shinpads – when the Blues won the Champions League in 2012.
Terry missed the final with Bayern Munich through suspension which Chelsea won on penalties.
But adorned in his full kit, Terry proceeded to run on and lift the trophy after the shootout – actions which led to widespread mocking among fans.
Explaining on A League of Their Own why he did it, Terry said: “I’ve got shinpads, tape, the lot, I went for it.
“I dreamed of that for years. After what happened in Moscow for me personally, to see the delight among the players we had, the squad we had and the fans too, it meant everything to me.
“I thought it was only right I was part of the celebrations.”