Last year, it was reported that Superbot Entertainment was working on a game code-named 'Title Fight', a brawler that will allegedly bring together Uncharted's Nathan Drake, Twisted Metal's Sweet Tooth, Killzone's Colonel Radec, Fat Princess, Kratos, Sly Cooper and PaRappa the Rapper.
SuperBot level designer Chris Molina fuelled speculation about the project with a subsequent Twitter post. He claimed that Sony's 'Michael' commercial, which features a range of its mascots, was "vaguely foreshadowing" his studio's "soon-to-be-announced title".
Nintendo's most recent entry in its crossover fighting series was Super Smash Bros Brawl, which arrived on the Wii in 2008.
Sony is yet to officially confirm that it is working on a crossover fighter of its own, with speculation suggesting that it could make an announcement at E3.