The pair go on to praise Angelina Jolie's tiger body art, which was inked by Thai monks using traditional techniques.
But they were less complementary about Cara Delevingne's "mess" of a tattoo - a lion on her hand which Oliver described as looking like a "turd smear".
By the time the pair get to critiquing Mike Tyson's facial art, they've given up even trying to be nice.
They joke: "This is the purest example of you just don't care anymore."
And they're just as uncomplimentary about Ed Sheeran's colourful sleeve, which they say looks like a child's crayon drawings.
Tattoos are evolving all the time, and we recently revealed some of the creative new places people are getting inked up.
Earlier this month, we told how new tattoo trends include getting inkings on your elbow, knees, or even your armpit.