Kermit the Frog joins the chorus – in 'Caligula'

New opera dresses characters as kids' favourites to portray citizens living in terror

It's time to play the music, it's time to light the lights – Kermit the Frog is in appearing in a tale of dictatorship, violence and sexual depravity.

Audiences will see the children's character, along with hero He-Man and clown Ronald McDonald, in a much darker way later this month when new versions take to the stage for English National Opera's UK premiere of the German composer Detlev Glanert's opera Caligula. Members of the chorus will wear costumes reminiscent of the famous figures of fun to represent a society living in terror. Other costumes will include those inspired by Miss World-style beauty-pageant contestants, show girls, a doughnut and a turkey. Costume designer Alice Babidge said that while people might associate the characters with "colour and movement and fun, light fluffy things", there were things that were "sad and different and frightening" about her surreal interpretations.

Based on Albert Camus' play of the same name, which he wrote as a response to Hitler and Stalin, Glanert's 2006 opera examines the rise of the modern dictator. Both versions chart the rule of the tyrannical and decadent Roman emperor Caligula, whose life, following the death of his sister and lover, Drusilla, loses meaning. He pursues a destructive path of cruelty, murder and depravity.

The ENO's production is the latest from the imaginative and acclaimed Australian director Benedict Andrews, who last month directed Hollywood star Cate Blanchett in Sydney Theatre Company's staging of Big and Small (Gross und Klein) at the Barbican.

The opera's 40-strong chorus represents Caligula's people. Andrews said their unusual costumes – which provide a contrast in Act II to the fine suits, fur and diamonds that characterise a wealthy society in the first act – are used "to portray the abused citizens of a totalitarian state". "They are examples of a populace living in terror, perhaps forced to dress up by Caligula. A senator says, 'It is all a dream. He will change all of his nightmares into corpses.' These unusual costumes help form a portrait of this nightmare society... a society whose ruler Caligula has gone insane."

Andrews, who last year directed the ENO's powerful production of The Return of Ulysses at the Young Vic, has set Caligula in a football stadium in a nameless, fictional state run by a military dictatorship. "The staging concept comes from studying images of ancient Roman stadiums, and of contemporary sports fields," he said. "I was struck how these places have been co-opted by the forces of state terror, ie the National Stadium in Chile under Pinochet... The stadium becomes filled with people, sometimes they seem to be real, at other times creatures from Caligula's imagination."

Artistic director John Berry said that Andrews, "one of the hottest directors" in theatre, not only had an "amazing visual sense" but was also a wonderful director of performers. He added that Caligula's score did not put any barriers in front of an audience new to contemporary opera. "It feels very modern but it also has a romantic air to it," he said. "It's emotional, it's atmospheric. It varies from absolutely explosive music that is highly technical to music that is incredibly simple."