Paul McCartney is reportedly mulling a collaboration with indie rock outfit Gorillaz, which would return him to the cartoon-based music world he inhabited for the Beatles' 'Yellow Submarine' movie.

You'd think McCartney would be too busy, what with a ballpark tour, a pair of catalog re-issues, a pop standards disc, a "heavier rock" album and even a wedding in his near future, but maybe all this activity keeps him young.

So far, Paul hasn't confirmed anything's in the works, telling the Quietus, "We have kind of talked. Nothing serious, but I like what they do. I have run into [Gorillaz leader] Damon [Albarn] at things and we have talked. It's got near a couple of times but we never had the time, I suppose."

NME seems to think things are further along, quoting a source stating "things are looking good for the future." If Paul does decide to join the fictional band of musical ape-pirates, he'll do so in the footsteps of fellow classic rocker Lou Reed, who appeared on 'Some Kind of Nature' from the Gorillaz' 2010 album 'Plastic Beach.'

Watch the Trailer for the Beatles' 'Yellow Submarine'