Family Guy’s” Comic-Con panel kicked off with a preview of the show’s much-anticipated Sept. 28 crossover with “The Simpsons,” in which the Griffin family visits Springfield.

Among the highlights from the sneak peek: Homer and Peter eat donuts and realize they have a lot in common; Bart and Stewie prank call Moe’s Tavern (and it escalates quickly); Peter attempts to get Homer to set up a cutaway gag; Bob from “Bob’s Burgers” makes an appearance; Stewie and Bart go skateboarding; Homer and Peter discover some unnerving similarities between Duff and Pawtucket Patriot Ale; and the duo get into a predictably destructive fight across Springfield’s most notable locations.

“Simpsons” creator Matt Groening also appeared during the panel to ask for the producers’ advice on how a young, struggling animator could break into the business, and told them to kiss his ass a little more.

On the panel, producers Steve Callaghan and Rich Appel teased a number of plotlines coming up in “Family Guy’s” thirteenth season. In the show’s “very special Christmas episode,” Jesus returns and the guys discover he’s a virgin, so they go about trying to get him laid. “We’re going to hell,” Mike Henry drawled in Cleveland Brown’s voice.

Another episode will see Liam Neeson guest starring. Every time Peter gets drunk, he’ll declare he can beat up Liam Neeson, so eventually his friends call him on it and they go to a film set to make him prove it. “He was very willing to poke fun at himself and all the internet rumors about him,” Appel said of Neeson. Other guest stars this season include Jeff Garlin, Allison Janney, Joe Buck and Julie Bowen.

Elsewhere in the season, Meg will be recruited to become a foot fetish model; Stewie will become pregnant with Brian’s baby; and Chris will fail his history test and subsequently go on a “Bill and Ted’s Excellent Adventure”-style trip through time with Stewie and Brian, “where we get to punch out Napoleon,” according to Seth Green.

After the success of the “Simpsons” movie, the producers admitted that they had begun work on a “Family Guy” film a couple of years ago, but the project is on hold because of Seth MacFarlane’s busy schedule. “Someday, we will make it happen,” Callaghan promised.

They also plan to introduce a number of supporting characters from “The Cleveland Show” onto “Family Guy” since the spinoff’s cancellation.

“That’s the best part about animation — even though that show went away, we can bring all those characters back to our show,” Callaghan noted.

One lingering mystery from last season was “who hit Brian with the car?” and a fan demanded to know the answer.

“It was Justin Bieber!” Green declared.

“We’ll go with that,” Callaghan agreed.

“Family Guy” returns with the one-hour crossover special, “The Simpsons Guy,” on Sept. 28 at 9 p.m. on Fox.