The Silly Song "Endangered Love". Larry + Manatee plushie = Pure hilarity.
What really sold it was Bob's reaction. "Maybe you should read a book..."
The show itself is pretty funny.
The lampshading of the lack of appendages in Dr. Jiggle and Mr. Sly.
Jonah came with a bonus feature of "Digital Dailies", which is pretty much Vischer, Nawrocki, and Hodge ad-libbing as Mr. Lunt, Larry, and Khalil respectively, as they go through animation errors and pretend that they actually filmed it. It's arguably funnier than the film.
Mr. Lunt (on Pa's outfit being completely black): Pa came on set thinking that it was Johnny Cash day.
Upon seeing an error in Khalil randomly floating on a cheese curl, they develop ideas for the sequel, Khalil and the Magic Cheese Curl.
When shown an unfinished 3D turnaround of Khalil, with nothing but his eyes and mouth, Khalil says it was the work of vanishing cream. And they speculate what the cube at his tail region is.
One of the alternate takes of Jonah for the camper scene had the van crashing into Larry-Boy.
In Jonah, everyone prays for Jonah's safety before he walks the plank - except for Larry, who prays for the duckie preserver Jonah wears. After Jonah is swallowed by the whale, both Pa and Lunt are shocked and dismayed at Jonah's fate - but when the duckie pops up out of the water, Larry gives a huge, unabashed happy smile.