ET's with Jim Carrey, his girlfriend Jenny McCarthy and more for the world premiere of Disney's 'A Christmas Carol' in London's Leicester Square, where Jim dishes about his festive animated film and hilarious holiday memories.

"When you get a chance to do great literature with an amazing cast … and a director with a vision and a track record of doing beautiful stories, you've just got to count your lucky stars," Jim tells ET.

"His performance is a tour de force. He's the best Scrooge ever," raves director Robert Zemeckis.

Meanwhile, the premiere broke four Guinness world records. One for the largest sing-a-long as 13,000 people sang "Silent Night." The other records were for the largest 3-D film premiere across 28 cinemas in the UK; the widest distribution for a 3-D film; and Zemeckis himself broke a record for being the most successful 3-D live-action film maker.

Disney's 'A Chrismas Carol' in 3D arrives in theaters this Friday. Click the video for more with Jim and his co-stars including Bob Hoskins and Colin Firth.