John Oliver reads hilarious YouTube hate mail: 'He's aged so much'

John Oliver's hilarious hate mail has been revealed.

He's away on holiday but John Oliver couldn't help but delve into his fan mail. Or, in this case, his hate mail.

Oliver delivered a YouTube video overnight in which he revealed some of the disturbing comments posted under his Last Week Tonight clips online.

One wrote, "John Oliver looks like a mix between a Pokémon and a child molester," while another said, "John Oliver's eyebrows are alien caterpillars and move independently of one another."

"He's aged so much," said a third, while another wrote that Oliver's show was, "uniquely boring".

But Oliver said the most "discouraging" thing he'd read was this comment: "At least you serve your corporate masters well, you unfunny live action Beaker."

"I was annoyed I hadn't thought of that myself," Oliver replied.

"I don't mind being insulted ... but it really hurts when I'm out-comedianned by them."

It wasn't all negative. Oliver read one out that simply said: "John Oliver has magnificent eyebrows."

Last Week Tonight returns from its break on July 25. It screens on SoHo in New Zealand.