'Bengal Tiger at the Baghdad Zoo'

The ghosts who wander the burning city in Iraq are a droll collection of lonely spirits -- excellent company, really, even if they are the maimed undead of wartime catastrophe.

Really excellent, too, is 2010 Pulitzer finalist "Bengal Tiger at the Baghdad Zoo," which marks both the Broadway debut of deliriously original playwright Rajiv Joseph and the first time Robin Williams has played someone other than himself on Broadway.

Williams is shrewd and admirably restrained — as the tiger, a mangy old guy in a scruffy beard and bum clothes whose tiger-eye view forms much of this surreal, cruel, darkly entertaining story about war and the nature of all us beasts.

It is 2003, and a marine (Glenn Davis) takes pity on the starving caged creature by offering a Slim Jim. Tiger bites off his hand, after which an even more callow marine (Brad Fleischer) — itching to see some action — shoots the animal with a gold gun plundered from the palace of Sadam's sons.

"I won't lie. When I get hungry, I get stupid," deadpans the tiger, as dislocated from his home as the jumpy soldiers with their befuddlement, bloodlust and greed. Meanwhile, over at a bombed-out office, a soulful gardener-turned-translator (the terrific Arian Moayed) gets sucked ever-deeper into the tragic insanity.

Earlier this year, Joseph — born in Cleveland to an Indian father and a mother from Ohio — made a smashing Off-Broadway debut with his two-character "Gruesome Playground Injuries." With "Bengal Tiger," he deftly moves onto a big fantastical canvas without losing the personal intimacy.

Director Moisés Kaufman expertly balances the horror and the outright absurdity. As people and this feline become ghosts, they mysteriously grow wiser. Sadam's dead son Uday (Hrach Titizian), walks around talking to his beheaded brother's skull.

Parade music, rap and calls to prayer are all accompanied by bomb booms. Iraqi Arabic is shouted without translation. None is needed. Derek McLane's ingenious set lingers lovingly on what's left of the huge topiary animals in Uday's garden. The tiger, trying in vain to atone for his "tigerness," wonders if his very nature is contrary to the moral code of the universe. Joseph, too clever to have to say the words, asks the same about war.

WHAT "Bengal Tiger at the Baghdad Zoo"

WHERE Richard Rodgers Theatre, 226 W. 46th St.

INFO $60-$135; 877-250-2929; bengaltigeronbroadway.com

BOTTOM LINE Deliriously original — even funny — war tragedy