Frank Skinner has unleashed on Simon Cowell saying the star's face looks like a Slipknot mask.
Simon, 59, unveiled a dramatic physical transformation recently after dropping 20lbs on a vegan diet but comedian Frank, 62, is not impressed by his altered appearance.
Speaking to Dave Berry on his Absolute Radio Breakfast Show, he went on a lengthy rant full of insults, beginning with: "I remember Simon Cowell when he had his first face. I've known him a long time.
"The current one is a bit Slipknot. It's actually quite terrifying. It looks like his nose is juggling his eyes. They are at different levels. A man of his money you'd think could get the best plastic surgeon in the world.
"I think it's to do with the power cuts we had recently, I think it was done in darkness. It really is shocking.
"If he was born like that you'd feel cruel saying it but as he's picked it out of a catalogue of some kind, I presume it was a double spread and there was a fold in the middle."
Simon has been open about his love of Botox in the past and, last year, revealed he had splashed out £2,000 on a Silhouette Soft Lift.
The 'X Factor' judge paid a visit to cosmetic surgeon Dr Jean-Louis Sebagh - known as the "Picasso of dermatology" - for a Silhouette Soft Lift, which involved sewing bioplastic-infused thread into the face and neck, to get rid of sagging skin.
He said: "There's lots of things you can do now. You don't just have to stuff your face with filler and Botox.
"It hurts like hell but it gets rid of sun damage and unplugs all the crap. For me now, it's all about having clean skin. If you have clean skin, you look better. But you have to be very careful with some of this stuff."
While the music mogul has made no secret of the fact he likes to experiment with different procedures, he previously admitted there was a time in the past when he had "too much Botox".
He said at the time: "Hopefully I look better now - I probably did have a little too much Botox a couple of years ago, because everyone on TV has it. Now I have facials, but nothing too extravagant at the moment. I have a girl who comes here and does a great face massage - it's very relaxing.
"I also had a sheep placenta facial once, which was quite out there. Then Sinitta recommended I try another detoxifying machine, and this thing turned up in my bedroom and it was like something out of Dr Who. It was like a spaceship had landed in my bedroom."