Show bosses today announced that Terry, played by Nigel Pivaro, will be back on screen in the spring - upsetting the lives of the Weatherfield residents.
Fountain, who has been playing Terry's son Tommy for nearly a year, discussed the big news during an appearance on Loose Women today.
"We've literally just found out about it, but we know that he's going to come back and he's going to cause trouble," Fountain explained.
"For me, I'm looking forward to it because it opens up a whole other side of Tommy that I can work with, and that nobody has ever seen before. I think he'll come to realise just what type of dad he's got!"
Fountain continued: "Tommy's been put as this womaniser, but this opens up a whole different side of his character - and it's going to test Tommy and Tina's relationship. To have Terry come back is really exciting."
Meanwhile, Michelle Keegan - who plays Tina - warned that her feisty character will take no nonsense from Terry.
She said: "I think Tina will give him a run for his money!"
> Coronation Street return for Terry Duckworth
> Read more Coronation Street spoilers and news
Watch a preview of Friday night's Coronation Street double bill in the video below: