I don't even know where to begin with this largely odd and plodding motion picture. "Rango" is an animated spaghetti western slapstick comedy with heavy hallucinatory asides and a taste for film references. Born from the screenwriter of "Gladiator" and directed by the man who launched and promptly sank the "Pirates of the Caribbean" franchise, "Rango" is a tricky film to summarize, but a fairly easy picture to ignore.

When his terrarium is smashed in the middle of the desert, a cloistered chameleon (Johnny Depp) is freed for the first time in his life, left out in the vast unknown with nothing but his dedication to the theatrical arts to protect him. Stumbling upon the drought-stricken town of Dirt, the jittery chameleon is forced to reinvent himself to survive in the gunslinger community. Becoming a hero named Rango, the wily lizard is soon made sheriff, tasked with keeping peace as the nervous residents confront the water shortage. With Mayor Tortoise John (Ned Beatty) providing little help, Rango and his posse, including romantic interest Beans (Isla Fisher), head off into the great unknown on the hunt for water, uncovering secrets and finding purpose in the sun-baked wasteland.

I suppose in the animated film realm, any semblance of originality should be cherished. While riddled with movie parody, "Rango" is a fairly original take on traditional cartoon antics, taking a droll route of comedy to expand the crusty adventures of a chameleon in over his head. However, it's a vacillating sense of humor, attempting to play to adults and kids with pratfalls and dark comedy, having a jolly time exploring body trauma and violent widescreen western traditions, reworked here to include a habitat of battered desert creatures poured into archetypal roles while retaining their animal instincts. Writer John Logan obviously scripts with attention, proudly displaying his film geek cred (the movie snatches plot and a few character designs from "Chinatown"), hunting down an irreverent tone that merges broadly animated behavior with true hero yearn, hoping to create meaningful chaos. The shifting tonalities don't blend smoothly, and worse, "Rango" doesn't feature a single bellylaugh.

Director Gore Verbinski is lost in the film's choreography, wrapped up in the striking western look, which is expertly animated down to the last itchy detail. "Rango" is a gorgeous picture, but its soullessness wears down the viewing experience. Caught between jokes and delusions, the picture doesn't build momentum, frequently stopping to soak in the stillborn antics of our hero, who employs his ease with acting to dupe Dirt into believing he's the man with a plan, encountering gangs of possums, fighting off predatory hawks, and staring down the dreaded Rattlesnake Jake (Bill Nighy), hoping to secure the companionship he's always wanted with fractured crush Beans. Verbinksi stages large-scale action sequences and adores tinkering with western convention, but he's leaking gas the entire way. "Rango" slows to a crawl when it starts to take the titular character seriously, providing pathos for an uncharismatic chameleon and his whiny partners in the water-hunting business.

"Rango" is an exercise in cleverness, and that detachment robs the picture of the joy it craves. Instead of getting caught up in Rango's existential crisis and six-gun sham, Verbinksi would rather show off his staging expertise, while Logan dreams up leaden jokes and cutesy cameos (Depp reprises his take on Hunter S. Thompson for a windshield gag). "Rango" doesn't build to anything substantial, instead dragging along interminably while its sense of humor succumbs to heat exhaustion.