Amanda Seyfried entertained her 'Les Miserables' castmates by rapping Eminem's 'Lose Yourself' while dressed as Kermit the Frog.

The entire cast got together at a karaoke night arranged by Russell Crowe before shooting the adaptation of the famous musical and Anne Hathaway revealed Amanda impressed everyone with her skills.

She told E! News: "You have not lived until you see something as adorable as Amanda wearing a green Kermit suit rapping to Eminem's 'Lose Yourself'.

"Russell arranged Friday night dinner for us all to bond and then he had a keyboard in his place and he had somebody play piano. We were all very nervous and self-conscious, but he got us all singing."

The bonding session helped the cast - which also includes Hugh Jackman - to relax and made filming the emotional musical easier.

Anne added: "And then all of a sudden when we went to work on Monday, we were all way more relaxed with each other and we didn't feel we had to say sorry for warming up, or like, we had to explain ourselves singing. It just kind of cut straight through all the b.s. and got us working together as a cast."