Since the early 20th century, the teddy bear has been a potent symbol of childhood innocence.

Stuffed animals can also be incredibly valuable: bears handmade by the German firm Steiff, distinguished by a button in their ears, are highly desirable to toy collectors.

In December 1994, Christie’s broke records when a Japanese businessman paid £110,000 for a 1905 Steiff bear called Teddy Girl. Evidently, these cuddly and comforting critters are not mere child’s play.

Ted is a deliciously foul-mouthed comedy that employs the magic of digital trickery to bring to life one rotund stuffed bear as a buddy for a lonely boy. Child and toy become inseparable and the furry scamp and his human owner embark on a series of deranged and debauched misadventures that fully justify the film’s 15 certificate.

It’s a simple premise — essentially a live action version of Toy Story — albeit with the eponymous bear accepted as a talking, skirt-chasing entity by everyone he encounters.

Writer-director Seth MacFarlane, creator of the irreverent animated comedies Family Guy and American Dad!, has great fun with his real and virtual characters, taking verbal pot shots at Susan Boyle, Taylor Lautner and Brandon Routh in a script that sticks up two fingers to political correctness.

“Here is the story of a little boy and his magical wish that changed his life forever,” intones the droll Narrator (Patrick Stewart), who transports us back to Christmas 1985, when a boy called John Bennett (Bretton Manley) stares adoringly at his favourite teddy and whispers: “I wish you could talk. Then we could be friends forever and ever.”

A shooting star passes overhead and next morning John introduces the animated Ted (voiced by MacFarlane) to his dumbfounded parents (Ralph Garman, Alex Borstein).

Fast-forwarding to the present day, John (Mark Wahlberg) now works for a car rental company and has a beautiful girlfriend, Lori (Mila Kunis). When their four-year anniversary dinner ends in a fractious discussion about priorities, John responds by asking his best buddy to move out of the apartment and stand on his own two paws.

Ted has a generous smattering of belly laughs, although some of the best moments have been repeated ad nauseum in trailers.

Wahlberg is perfectly suited to his role as a goofy hopeless romantic and screen chemistry with Kunis simmers, if it never quite boils. Digital effects are excellent, seamlessly melding the bear with live action in hare-brained action sequences, including a hysterical hotel room punch-up and a climactic race around a sporting venue that may have grown men choking back tears.

Wise-cracking tyke Greg Heffley (Zachary Gordon) is looking forward to spending the summer in front of a TV playing video games in Diary of a Wimpy Kid: Dog Days. But his mother Susan (Rachael Harris) has other ideas and encourages her husband Frank (Steve Zahn) to engage with Greg, enrolling the lad in the Wilderness Explorers so they can spend quality time together in the great outdoors. “Me and my dad have nothing in common. As long as I stay one step ahead of him, I think I have a shot at a great summer,” Greg assures us. So the youngster lies about landing a job at the local country club, where he hopes to win the affections of pretty classmate Holly (Peyton List), who gives tennis lessons to local kids. In order to impress Holly, Greg suggests a boys versus girls doubles match with loveable best friend Rowley (Robert Capron) and arch-nemesis Patty (Laine MacNeil).

Diary of a Wimpy Kid: Dog Days is the weakest chapter so far. Bowers’s soulless sequel contrives several flimsy set pieces — Greg losing his swimming trunks as he tumbles from a diving board, a disastrous sweet sixteen party — that fail to raise a smile. The father-son bonding is saturated with sickly sentiment, hammering home the life lesson: “A man who never made a mistake, never made anything.”

As portrayed on the big screen, Greg is deeply selfish, so we struggle to muster any sympathy for the brattish protagonist as his tower of little white lies collapses around him.