This holiday season, the multiplex smells like a manger. Just as puppies and kittens are arriving under Christmas trees, movies with critter characters are arriving in theaters.

Pulling the wagon is ” War Horse,” Steven Spielberg’s battlefield epic about a stalwart stallion that is conscripted into World War I. The movie opens nationwide on Christmas Day.

The menagerie in the heart-tugging true story ” We Bought a Zoo” features more than 70 trained animals, including lions, tigers and Crystal, the capuchin monkey from “The Hangover: Part II.”

Virtual varmints hog the spotlight in the ‘toons ” Alvin and the Chipmunks: Chipwrecked” and ” Puss in Boots.”

True-life traumatized animals are featured in the family drama “Dolphin Tale” (newly released on DVD) and the recent documentaries “Buck” (shortlisted for an Academy Award) and “One Lucky Elephant” (about the pachyderm namesake of St. Louis’ Circus Flora).

But as is often the case, most of this year’s cinematic scene-stealers are dogs.

In the critics’ favorite ” The Artist,” the life-saving companion of a down-and-out silent-movie star is a Jack Russell terrier. Another Jack Russell is prominent in the art-house hit “Beginners.”

In the new ‘toon ” The Adventures of Tintin,” a fox terrier called Snowy plays the Dr. Watson to a journalistic Sherlock.

In Martin Scorsese’s “Hugo,” a menacing Doberman hunts for orphans in a Paris train station.

And in the comedy “Young Adult,” the only warm-blooded creature who can tolerate tipsy novelist Charlize Theron is the Pomeranian she keeps in her handbag.

The dog named Hummer that plays that role was discovered by director Jason Reitman while it was walking with its owner down a New York street. As Reitman told the New York Times, the dog was perfect for the part because Pomeranians have a permanent smile, implying positive regard for the Theron character.

Of course, dogs have long been movie mainstays because they have expressive faces and are more easily trainable than, say, cats. Terry, the Cairn terrier who played Toto in “The Wizard of Oz,” was paid more than the Munchkins and appeared in a dozen other movies. Uggie, the 9-year-old Jack Russell terrier in “The Artist,” also was featured in the recent movie “Water for Elephants” (and is the subject of a tongue-in-cheek Facebook campaign to name him best supporting actor). Cosmo, the Jack Russell in “Beginners,” was trained by Mathilde de Cagney, who also trained the dog Eddie in the TV series “Frasier.”

Trainers are the unsung heroes of such productions. More than 30 of them worked on “We Bought a Zoo.” On the set of the 3-D “Hugo,” de Cagney was dressed as a character in the train station so she could monitor the Doberman’s movements.

“Buck” documents how trainer Buck Brannaman was a real-life horse whisperer for the movie of the same name — and how creatures of both species respond better to reward than punishment.

For “War Horse,” there were two horses, named Finder and Abraham, who divided the role of Joey and were trained to charge through a World War I-era hellscape of explosions, trenches and barbed wire (which was actually rubberized Styrofoam that the horses found pleasantly ticklish).

That war produced a real-life animal hero who became one of the biggest stars in cinema. In 1918, an American colonel named Lee Duncan entered a bombed-out kennel in France and discovered a German shepherd and her five starving puppies. While the other dogs were divvied among the soldiers, Duncan named one of the puppies Rin Tin Tin and eventually took it back to America with him. On the set of a silent movie, the gallant dog did a stunt for a Warner Bros. producer and was signed to a contract.

Rin Tin Tin made 18 movies and even starred in a radio serial. As noted in a new biography by Susan Orlean, the “wonder dog” was so popular in 1928 that he earned the most votes for the inaugural Academy Award for best actor. The academy then changed its rules to preclude nonhumans. But that rule would change if the new breed of animal actors learned to speak. (And maybe with the translator technology that was featured in the recent ‘toon “Up,” they can.)