Brad Pitt says his new son Knox Leon looked like Russian Prime Minister Vladimir Putin when he was born. The 'Fight Club' actor - who welcomed twins Knox and Vivienne Marcheline with partner Angelina Jolie into the world on July 12 - was surprised by his children's unique looks.

He said: "I dare to say that Vivienne is proving to resemble Angelina in spirit, attitude and physicality. She is quite elegant like her mother. And Knox - he's a bit of me. He likes music like his dad. But when he was born he looked like Vladimir Putin!"

Angelina Jolie was not maternal when she was younger. Her father Jon Voight - who recently rekindled his relationship with his estranged daughter - admits he is amazed she now has six children because she didn't display mothering instincts as a child.

He told Us Weekly magazine: "You know she wasn't the kind that played with dolls and then all of the sudden she has all of these children."

Jennifer Aniston and John Mayer are planning a "trial marriage." The couple - who have been dating for three months - are said to be keen to test the strength of their relationship, and think John moving into Jennifer's house is the perfect first step.

A source said: "John wants to settle down as much as Jennifer does."

The 33-year-old actress - who gave birth to twins, the fifth and sixth children she raises with partner Brad Pitt, earlier this month - is said to be in final negotiations with studio bosses to play the feline villain who first appeared in the Batman comics.

Angelina has already been approved for the role by Julie Newmar, who played Catwoman in the "Batman" TV series from 1966 to 1968.

The Hollywood couple - who welcomed twins Knox Leon and Vivienne Marcheline into the world on July 12 - have six children, but are determined to continue expanding their brood.

A source said: "Angelina wants one more baby naturally - even if they end up having twins again. Twins would be wonderful. A dozen kids would be their dream."

Angelina Jolie and Brad Pitt reportedly conceived their twins using in vitro fertilization.

The couple - who welcomed Knox Leon and Vivienne Marcheline into the world on July 12 - were reportedly so desperate to add to their ever-expanding brood they turned to IVF infertility treatment in a bid to conceive.