Pop singer Alecia Moore (P!nk) replaces Brittany Murphy as Gloria. Coincidentally, Pink sang a cover version of 'Tell Me Something Good' for the first film which can be heard in the opening credits.
The roles for Bill and Will the Krill, voiced by Matt Damon and Brad Pitt, were initially offered to Stephen Colbert and Jon Stewart. They had to turn them down due to scheduling conflicts.
There are an estimated 500 trillion krill, making them the largest animal population on Earth.
When asked if he had any plans for Happy Feet 3, George Miller responded, "if you put a gun to my head and said, 'You have to come up with a story for Happy Feet 3,' I'd say shoot me. I would have no idea."