Tyson Fury claims he could beat world heavyweight champion Deontay Wilder with one hand.
Fury, the former WBA, IBF, IBO and WBO champion, is returning to the ring after an absence of more than two years on June 9.
Fury, who has battled with mental health and weight problems during his time out, says some disparaging remarks from current WBC holder Wilder provided the prime motivation to reignite his career.
Speaking at a press conference, Fury said: "It was really Deontay Wilder who spurred me on and gave me the ambition to return. He said I couldn't do it. He said,' Tyson Fury, he's done'.
"And I was walking along the canal with my dog at the time, I thought, 'You know what, I'm a fat pig. Look at the state of me'. I felt like jumping in the water and drowning.
"Then I thought I'm going to turn this around and knock him out. I can tie one hand behind my back and beat Wilder.
"They can pick which one they want, left hand, right hand. That's how confident I am in my own ability."
The opponent for Fury's comeback fight, which will take place in his home city of Manchester, is still to be named but he hopes to be back in world title contention within two or three bouts.
By then Wilder could have fought Anthony Joshua, who now holds Fury's former titles, in a unification fight.
Fury claims neither fighter holds any fear for him.
The 29-year-old said: "When I'm ready for these guys, in a couple of fights, a couple of warm-up fights, then I'll take them. I'll take on anybody, I don't fear anybody.
"They're all very good fighters and champions but I think my talent, confidence and skill alone is enough to beat these fellas."
There has been speculation Fury will return to action against Nuri Seferi, a veteran Albanian cruiserweight but promoter Frank Warren would not confirm.
Warren said: "We're working on it and will name him (the opponent) in the next couple of weeks."