The most eyebrow-raising moments from the Oscars opening monologue (not even Hailey Bieber was safe).

Jimmy Kimmel is no stranger to the Dolby Theatre stage, having hosted the Academy Awards three times before.

So, when he was invited to host for the fourth time, he made sure to take no prisoners in his opening monologue. 

Watch: Top 5 Award Show Fails. Post continues below.

From making fun of nepo babies to addressing Robert Downey Jr.'s former drug addiction, here are all the controversial things the late-night host said during the 96th Academy Awards.

He addressed Greta Gerwig's snub.

When Barbie director Greta Gerwig failed to pick up a nomination in the Best Director category, people were outraged. So, of course, in true comedian fashion, Kimmel had to address it.

"Now, Barbie is a feminist icon, thanks to Greta Gerwig, who many believed deserved to be nominated for Best Director tonight. Hold on a second. I know you’re clapping, but you’re the ones who didn’t vote for her, by the way. Don’t act like you had nothing to do with this," he said.

He made a dig at Robert Downey Jr.'s former drug addiction.

Robert Downey Jr. may be at the top of the world now but years ago, the Oppenheimer star was battling a serious drug addiction. Despite being clean for a long time now, Kimmel couldn't help making a dig at his past.

"This is the highest point of Robert Downey Jr.’s long and illustrious career — well, one of the highest points," Kimmel joked. 

This prompted Downey to gesture at his own nose, to which Kimmel responded: "Was that too on the nose or is that a drug motion you made?"

He poked fun at one of the worst movies of the year, Madame Web.

You don't need to be a movie buff to know that Madame Web is one of the worst movies of the year so far, and it suffered another blow today in Kimmel's monologue.

"It was also a great year for movies, despite the fact that everything stopped. The people in this room somehow managed to come up with so many excellent films and memorable performances. This night is full of enormous talent, and untold potential, but so was Madame Web."

He questioned the length of Killers of the Flower Moon.

If you sat through Martin Scorcese's Killers of the Flower Moon from start to finish, then you should be the one winning an Oscar today, because the film is three and a half hours long.

In fact, most of the Best Picture nominees were over two hours long, according to Kimmel's research.

"There were so many great movies that held audiences captive this year," he said. "And I mean that literally. Your movies were too long this year. The average length of the top ten movies was two hours and 23 minutes. That’s up 30 minutes from three years ago. When I went to see Killers of the Flower Moon, I had my mail sent to the theatre. It’s so long, you could drive to Oklahoma and solve the murders yourself."

He roasted nepo babies. 

Hailey Bieber, who didn't even attend the ceremony, found herself at the butt of Kimmel's jokes, during a bit where he both criticised nepo babies and Hollywood in general. 

"Heavily botoxed, Hailey Bieber smoothie drinking, diabetes prescription abusing, gluten sensitive nepo babies with perpetually shivering chihuahuas…," said Kimmel, taking a jab at those who benefit from having connections in the industry.

Hailey, who is the daughter of movie star Stephen Baldwin, has a signature smoothie named after her at the US grocery store Erewhon.

Feature Image: Getty.