Jay Ward’s irresistibly daffy cartoons of the early 1960’s were charming and witty, with a post-modern meta wink at the fourth wall, wacky puns, and jokes that kids would suddenly remember and understand years later.  This reboot is smarmy, overblown, dumbed down, and off-kilter.  Who thinks it is a good idea to have a movie for children about time travel begin with a trip to the French revolution and the guillotine?

Cartoonist Ted Key, best known for the Hazel character played by Shirley Booth in the television sitcom, came up with the super-genius dog, Mr. Peabody, inventor of the WABAC machine, and his boy Sherman, for Ward’s “Rocky and Bullwinkle Show.”  In each episode, the duo would go back in time and somehow help a historical character solve a problem.  In this computer-animated, 3D, full-length feature version, the wit of the original devolves into bathroom humor and slapstick.  If the poster slogan is a doggie potty joke (“He makes his mark on history”), it is not a good sign.

As in the original, Mr. Peabody (“Modern Family’s” Ty Burrell) knows everything.  He’s a Nobel Prize-winning scientist who advises world leaders and makes a mean cocktail.  In one of the movie’s highlights, he is challenged to play musical instruments ranging from a flamenco guitar to a didgeridoo, and performs flawlessly.  He has invented a WABAC machine to take Sherman back in time, where they have encountered a cake-loving Marie Antoinette, with Mr. P led to the guillotine, and an unhappy Mona Lisa (Lake Bell), refusing to smile for Leonardo da Vinci (Stanley Tucci).

He has an adopted son, Sherman (Max Charles), who attends a fancy private school, where a girl named Penny (“Modern Family’s” Ariel Winter) gets angry when Sherman corrects her answer about George Washington chopping down the cherry tree, explaining that it never really happened.  After a sloppy misuse of the term “sarcastic,” she insults Sherman in the lunchroom, calling him a dog because he has a dog for a father.  They get into a fight, and Sherman bites her arm.  Mr. Peabody is called to the principal’s office, where Ms. Grunion (Allison Janney), a representative from Child Protective Services, tells him Sherman will be removed from the home if he is not an appropriate parent.

Mr. Peabody invites Penny and her parents and Ms. Grunion over for dinner to straighten things out.  Sherman shows Penny the WABAC machine that Mr. Peabody invented to take them back in time, and soon the two kids find themselves in ancient Egypt, where Penny becomes engaged to the young King Tut, until she finds out what that entrails, I mean entails (the bad pun thing is contagious–parents be warned).   Soon they are zipping around through history, meeting up with Agamemnon (Patrick Warburton, hilarious as always, despite an Oedipus joke) and soaring over Renaissance Florence in one of da Vinci’s flying machines.

The time travel plot gets bogged down in time-space continuum anomaly mumbo jumbo.  Then there are the father-son issues.  Mr. Peabody, who wants his son to call him Mr. Peabody, has a problem with the l-word.  Ms. Grunion’s blustery bullying and threats to remove Sherman from his home will make some families uncomfortable.  It should also make them uncomfortable that the movie appears to portray kidnapping a woman as a romantic gesture that should make her instantly fall in love.  Jokes about Oedipus and Bill Clinton are particularly disappointing.  Warburton’s dry delivery and some good scenery and action sequences can’t make up for the fact that this movie is a disappointing come-down that completely misses the charm and humor of the original.

Parents should know that this movie has a lot of potty humor, some crude jokes, cartoon-style peril and action including a guillotine and a taser, a character is presumed dead but later shown to have survived, a woman is captured as a romantic gesture, and child protection services challenges an adoption and attempts to remove a child from his home.

Family discussion:  If you could go back to any time in history, what would it be?  Who would you want to meet?  Why was Penny so mean?

If you like this, try: The original series and the other Jay Ward classics like “Rocky and Bullwinkle,” “Fractured Fairy Tales,” and “Dudley Do-right.”