Robert Downey Jr. decided that his version of Doctor “Dolittle” — not having to sing — would speak in a sort of gulped whisper of a Scots accent, with quiet, hoarse line readings that demand attention — or subtitles.

He becomes, in light of the movie he fronts this time out, the real “dog whisperer.” Because that’s the kindest description of this lifeless animated kiddie adventure comedy and its star’s paycheck-performance in it.

There are Oscar winners on screen and in the voice cast, because every animal, from Yoshi the polar bear (John Cena) to Poly (sic) the parrot (Emma Thomson) must have a star’s voice.

That becomes a game for the grownups watching this — “Isn’t that Craig Robinson as the squirrel, Octavia Spencer as the cranky duck, Rami Malek as the meek gorilla, Ralph Fiennes as the tiger and Kumail Nanjiani as Plimpton, the ostrich?”

That’s what one does when bored with a movie is as colorfully joyless as this digitally-animated menagerie, fronted by Downey, Michael Sheen, Jessie Buckley and Jim Broadbent as the humans on the screen.

The fantasy is set in the reign of Queen Victoria (Buckley). She is sick, and the reclusive Dolittle, in mourning since the loss of his adventurer/naturalist wife, is summoned. As he can “talk to the animals” that live in the palace, maybe they can tell him what’s up.

It turns out, they can. But before he can ascertain who is up to what, he’s diagnosed her as poisoned, with the only antidote on a far-off island he once visited.

There’s nothing for it but to set sail, with several of his animal friends – Poly is the boss — and this new boy (Harry Collett) he’s just met as his assistant.

The old rival/palace physician (Sheen) shadows him in a fanciful and menacing steam frigate.

Their adventures include a run-in with another old rival, King Rassouili (Antonio Banderas), and tests where — as in the “Wizard of Oz” — characters find inner resources they didn’t realize were there.

Chee Chee (the Oscar-winning Malek) has to get over his “I’m more of a cheer-quietly-from-the-sidelines kind of gorilla,” Plimpton the ostrich (Nanjiani, the funniest voice in the cast) has to learn to trust the polar bear — “You should be an Eskimo’s rug by now!”

Dolittle? He must get over his “I don’t care about anyone or anything anywhere any more.”

The animal animation is photo-real, but lifeless. The decision to hire the fellow who wrote “Syriana” and “Traffic” and “The Alamo” as director and co-writer feels more wrong-headed with every passing whimsy-free moment.

Sheen and Banderas make their characters fun, but they’re the only ones.

Because nothing that happens here overcomes the fatal decision the star made in choosing how Dolittle speaks. This is Johnny Depp in “Mortdecai” awful, a vocal choice so bad that Sheen’s rival doctor comments on Downey’s decision in what sounds like the only ad-lib in the movie, a comment on the script and Downey’s performance of it more damning than anything I could come up with.

Dolittle’s whisper is “all ‘lean in, I’m about to say something INTER-esting!”

Only he never does.

MPAA Rating: PG for some action, rude humor and brief language

Cast: Robert Downey, Jr., Antonio Banderas, Michael Sheen, Jessie Buckley, Harry Collett, Carmel Laniado and Jim Broadbent, with the voices of Emma Thomson, Selena Gomez, Marion Cotillard, Kumail Nanjiani, John Cena, Ralph Fiennes, Rami Malek and Craig Robinson.

Credits:  Directed by Stephen Gaghan, script by Stephen Gaghan, Dan Gregor and Doug Mand, based on the “Doctor Dolittle” books of Hugh Lofting. A Universal release.

Running time: 1:46