“Captain Underpants: The First Epic Movie” is childish and silly.

That's hardly a surprise, though, to anyone in the animated feature film’s target audience who has read one of the 70 million books sold worldwide featuring the rotund hero or the elementary-school students who created him.

The important thing is this: Although the production doesn't reach for intellectual grandeur, it is, on a very basic level, one of the funniest movies of the year.

Those who still giggle when someone mentions that the seventh planet from the sun is Uranus should prepare to blow some laugh snot bubbles. If that planetary joke seems crass, then you should skip the movie or lighten up a little.

The film follows relatively closely to the series of books written and illustrated by Dav Pilkey. Director David Soren opts to use a little higher-quality computer-generated style of animation, giving the characters more substance but also keeping the essence of the characters and stories true to the source.

The fruit of the lunacy starts with George and Harold (voiced with great childish glee by Kevin Hart and Thomas Middleditch), two elementary-school buddies who spend more time pulling pranks than studying. The best buds are also the masterminds behind a series of comics featuring Captain Underpants, a hero who fights evil dressed in only his tighty whities.

Their hijinks and the time spent on creating the comic books have attracted the wrath of the school principal, Mr. Krupp (Ed Helms). His plan is to split the friends by putting them in different classes; before he can make the move, though, George and Harold hypnotize Mr. Krupp into believing that he’s Captain Underpants.

The tactic proves helpful when the school gets a mad scientist, Professor Poopypants (Nick Kroll), as the new science teacher. The work is only Poopypants’ day job, as he has a diabolical scheme to end all laughter, starting with the students at Jerome Horwitz Elementary School.

Hart brings his usual energy to his role, and Soren gives him just enough room to make his voice work without going too far. Middleditch, Helms and Kroll turn in solid work, too, but the spark plug is Hart.

Nicholas Stoller’s screenplay (he wrote the script for the funny “Storks”) never gets more complicated than good vs. evil. That’s in step with the books and keeps the movie from falling into that sort of plot funk that plagued “The Boss Baby.” A simple story leaves more time for silly jokes and lighthearted humor.

The way Soren mixes the animation styles combined with the main characters speaking to the audience makes this less like a typical animated offering and more like an episode of a live-action children’s program such as “Pee-wee’s Playhouse” or “The Weird Al Show.” Part of the Yankovic vibe also comes from the music parody master’s “Underpants” theme song. It’s also very juvenile in lyrics, but that fits perfectly with the rest of the movie.

The film starts with a bang and ends with a boom, with little time to breathe in between.

Its lone weakness: The movie, like the books, is extremely male-dominated with only a few female characters.

That’s only a small problem with what is generally a fun movie experience — as long as you’re willing to laugh at schoolyard humor.