Andy Serkis wanted to highlight Cletus Kasady's "sense of humour" in Carnage.

The 'Venom: Let There Be Carnage' director has opened up on the upcoming sequel and explained his approach to the symbiote and how he is impacted by his human alter ego, played by Woody Harrelson.

He told IGN: "With all symbiotes, they reflect the person who is their host. So the darkness of Carnage, the playfulness, the wit, the strangeness.

"Cletus has a real intelligence and… a real sense of humour, and we wanted to reflect that in the symbiote that is linked to him."

The trailer - which was released this week - shows a few changes to Cletus after he first appeared in the post-credits scene in YEAR's 'Venom', when he was interviewed by Eddie Brock (Tom Hard).

The wig Harrelson's serial killer character was seen wearing in that initial appearance has been ditched, and Serkis noted there was a creative reason behind the change.

He said: "We wanted to give a sense that he's been in there for some time and that he's gone through various changes. ... so that we could really [see] what's going on with the darkness of the character."

Another change in the trailer is drawing on the walls of Cletus' cell, which weren't present in the post-credit scene.

However, they have been highlighted in the trailer and Serkis noted the importance of using them to show the child-like creativity of the character.

He added: "His cell is completely covered with these really bizarre markings and expressions. It's like his anger and frustration and his sadness and his desperation and his loneliness."

The movie - set to finally hit the big screen on September 24 - will also feature the debut of 'Spider-Man' villain Shriek and her alter ego Frances Louise Barrison (Naomie Harris).