Back in 2015 we saw Krystyna and her hypno-dog Princess put BGT audience members and hosts Ant and Dec to sleep.
She then went on to hypnotise Simon Cowell making him fall to sleep at his desk.
"It's almost like your brain tells you to do something which you shouldn't be doing but you just go along with it," Simon recalled. "The next thing is, you've actually fallen asleep.
"I always said I wanted to find a cat that could play the guitar. I think we've done pretty well finding a dog that can hypnotise people!
"I just want to own the dog. I could literally rule the world with this dog because all it does is stare at you and you do whatever it wants."
However as Princess retires from the spotlight, Krystyna has opened up about "the truth" behind the act.
"I've decided to tell the truth because Princess is retiring," she said to the Daily Mail newspaper. "It's not fair to string everybody along and let them believe she has super powers when she doesn't have any.
"It's not that Princess has powers - she's just an ordinary dog - it's that people believe she has powers."
Krystyna explained: "It's all about belief, I have to make her victims believe they are going to be hypnotised by a dog. I have had some doubts about revealing the truth, but it's part of my story because the work I am trying to do now is getting people to realise that they are hypnotised by loads of things in everyday life and they just don't realise.
"I've had an absolutely hilarious journey and have had the chance to meet so many celebrities who all say they have been terrified or really excited to meet me.
"It does make me laugh when I look back at all the people I've hypnotised and they believe that the power lies with the dog."
Who'd have thought it?!