15. Conker
Originally an all-ages mascot platformer like any other, Rare saw that Conker would potentially be lost in the fold, and gave their latest project a makeover infused with all of the adult humour and themes which were popular with fans of South Park and other 90s fare at the time. The new and more vulgar version of the anti-heroic squirrel would make for an interesting animated feature to be sure, but one that only those 18 and over would be able to purchase tickets for. Conker would be far from alone in the adult-only animated characters club, too. Fritz the Cat, Heavy Metal, Team America: World Police, and the aforementioned South Park have all shown that there is indeed an audience for silver screen animated features which are too mature for a younger demographic. The best part of course, would have to be the potential for musical numbers. Who among us can honestly say they would not love the song of "The Great and Mighty Poo" to become a mainstream hit?