The guest claimed her 15 stone pig George makes the best companion as she "swapped her husband" for the animal.
As the enormous pig entered the studio, Holly leapt on the sofa in fear, with George racing around the table to get near to her.
Viewers were in hysterics as Phillip Schofield's co-star lifted her legs out of the way, clearly scared of the huge animal.
One fan Tweeted saying: "Holly really ain’t feeling that pig" with laughing face emoji.
While another wrote: "Holly scared of the pig" adding a laughing face emoji to their tweet.
Holly exclaimed while getting as far away from the pig as possible: "I'm just not very good with things like this."
Her co-host Phil was definitely not as afraid of George as she was.
He went as far as to give the pig a kiss on the nose, as George's owner said he would lean in if you said 'kissy kissy".
Sceptical at first, Phil said: "He might bite my face off."
Georges owner replied: "I don't think he will" to which Phil shot back: "You don't think he will?"
Fans were in hysterics after Phil knelt down on the floor and lent into the pig to give him a peck.
One said: "Watching Phil crawl on the floor and kissy kissy a pig is highlight of my day."
While another wrote: "Nothing as funny as seeing Phil on his hands and knees on This Morning saying 'kissy kissy' to a pet pig.
"Brightened up my day."
This Morning continues tomorrow at 10am on ITV