Joe Bugner said he is "not a happy man" ahead of entering the 'Im A Celebrity... Get Me Out Of Here!' camp.
The former boxing pro - who has squared up to Muhammad Ali and Joe Frazier in the ring - said he's nervous about spending nights under the stars as a member of the jungle camp.
He said: "I do have butterflies. I'm nervous with anticipation. I've never slept under a jungle canopy and I'm worried about all the creepy crawlies and things so I'm not going in as a happy man.
"As a sportsman I'm pretty competitive and I think the jungle will be no exception. I'm definitely in it to win it."
Joe, 59, replaces 'Strictly Come Dancing' star Camilla Dallerup, who walked out of the jungle after just three days, saying she feared for her health.
Ahead of leaving she said: "I feel really weak like I could faint any time. I'm a small person and I don't have any reserve to draw on.
"I just felt this was the worse I've ever felt. I just have to listen to my body. I had to admit today that I'm not adjusting to this environment. My body has just not reacted well. I feel completely empty."