World War Z trailer swarms online

Brad Pitt and a zombie apocalypse... there's something you don't see every day.

After months of secrecy, the trailer for 'World War Z' has arrived, and it's eye-popping stuff.

Watch it below.

The forthcoming big-budget blockbuster - which has turned Pitt into an honorary Brit, after decamping his family to the UK for filming —-pulls no punches, beginning all domestic and lovely before rapidly turning cadaverous and catastrophic.

For the rumours of rifts between Pitt and director Marc Foster, the action looks to be first class.

And as far as zombie bundles go, this must be a record-breaking effort, taking the lead from '28 Days Later' in turning the undead from shuffling dunces into swarming Olympic sprinters.

The film, adapted from Max Brooks' novel of the same name, finds Pitt playing Gerry Lane, a UN man who is drafted in to interview survivors of 'World War Z', the aforementioned zombie apocalypse.

The rights to the book were reportedly the centre of a bidding war between Pitt's production company Plan B and Leonardo DiCaprio's Appian Way, but Pitt won out.

Alongside him in the cast are Mireille Enos, Matthew Fox and Bryan Cranston.

It's due out on June 21, 2013.