A fresh big-screen updating of late producer-writer Jay Ward's "Peabody's Improbable History" segments from his 1960s cartoon series "The Rocky and Bullwinkle Show," "Mr. Peabody & Sherman" is destined to win over a whole new audience previously unfamiliar with the unlikely title father-son team and their WABAC (pronounced "Way Back") Machine. Rambunctiously directed by Rob Minkoff (2008's "The Forbidden Kingdom") and written by Craig Wright (a former TV scripter for "United States of Tara," "Lost" and "Six Feet Under"), this swirling, pun-heavy time-traveling farce gets its smartly written part-wacky/part-sweet tone exactly right. Look closer still, and there is also a valid, timely allegory involved about families coming in all forms and what truly constitutes a good parent.

A Nobel Prize-winning scientist and captain of industry, Mr. Peabody (voiced by Ty Burrell) knew from an early age that he was different from all the other canines at the dog orphanage where he grew up. Favoring intellectualism over frivolity and heart-on-his-sleeve emotion (while the other pups ran around playing, he preferred reading Plato), an adult Peabody nevertheless goes to court for the right to adopt human boy Sherman (Max Charles) when he finds him abandoned in an alley. The two of them make a perfect pair, Peabody's secret invention of the WABAC Machine allowing them to zip through time and learn about history. When Sherman defends himself from bullying classmate Penny Peterson (Ariel Winter) and gets in trouble at school for it, social services worker Ms. Grunion (Allison Janney) threatens to take him away from Mr. Peabody if her investigation finds that he's living in an unsuitable home environment. Hoping to make amends and put the whole issue to rest, Mr. Peabody invites Penny and her parents, Paul (Stephen Colbert) and Patty (Leslie Mann), over for dinner. Unfortunately, Sherman's efforts to befriend the snooty Penny drives him to reveal the WABAC Machine—a contraption that zaps her to Ancient Egypt. Hastily hypnotizing Penny's mom and dad, the father-son duo begin a race through time to bring the young girl back to the present day.

"The Time Machine," "Bill and Ted's Excellent Adventure" and "A Goofy Movie" get swirled into a bouncy, effervescent comedic fantasy package in "Mr. Peabody & Sherman," a franchise in the making with two lovable protagonists and a premise that lends itself to limitless further adventures. Whether Peabody is narrowly escaping the guillotine at the 18th-century Palace of Versailles, Penny is facing a marriage with a boyhood King Tut in Ancient Egypt, or the three of them are meeting Leonardo Da Vinci in 1508 Florence as he paints the Mona Lisa, the movie keeps moving and reinventing itself. Mr. Peabody is not shy with tricky wordplay ("You can't have your cake and edict, too," he muses after his run-in with Marie Antoinette), while plenty of sly jokes about everyone from Oedipus to Bill Clinton will keep older audiences just as entertained as the kids.

One element that brings levity to the picture, turning it into more than just a boisterous slapstick diversion, is the touching relationship between Mr. Peabody and Sherman. The former might be a dog and the latter a human, but this alternate computer-animated vision of the world makes the point that what is most important in a family is the love and care between each other. Although Peabody is uncomfortable with exposing his full emotions at the onset—when Sherman tells him he loves him, he can only bring himself to reply, "I have a deep regard for you, as well"—through their experiences and the unimaginable threat of getting split up the dog genius has a much-needed epiphany about how much Sherman genuinely means to him. In a simple, lovely early montage scored to John Lennon's "Beautiful Boy," Mr. Peabody is reminded of all the memories they share as he passes by a wall of photographs. It's a great little segment that helps immeasurably in developing them as a sympathetic father and son worth rooting for.

With all of their cavorting through eras past, the space-time continuum is bound to face a dreaded paradox. The third act of "Mr. Peabody & Sherman" is imaginative in the use of this conundrum, approaching screwball levels of hilarity. The actual logic of such a situation doesn't exactly hold up to scrutiny, but the script is cleverly conceived all the same and will give kids in the audience something extra to think about if they so choose. The film's biggest achievement is in its characters and their chemistry, particularly that of Mr. Peabody and Sherman, and Sherman and Penny, who gradually realizes how wrong she was to mistreat a boy just because his dad is different than he. Ty Burrell (2012's "Butter"), Max Charles (2012's "The Amazing Spider-Man") and Ariel Winter (2010's "Killers") form a copacetic unit as Peabody, Sherman and Penny, the voice work immediately inspired and warmly felt. The same could be said about the movie as a whole, in all of its big-souled, splendidly animated enthusiasm.