If Fox’s new Saturday night cartoon “Axe Cop” (11 p.m.) feels like it was made by a child, you’d be half right. The debut entry into the network’s Animation Domination High Definition (ADHD) block of adult cartoons is based on a webcomic created in 2009 by then-5-year-old Malachai Nicolle and his cartoonist brother, Ethan Nicolle (who was 29).

For something that’s supposed to be adult in nature — and is directly competing with Cartoon Network’s Adult Swim — “Axe Cop” the TV series is far too juvenile.

Which is a shame, because the talent is there: Nick Offerman voices Axe Cop, a gruff and manly crime-fighting police officer who prefers his fireman’s ax to a gun. The voice cast includes Offerman’s wife, Megan Mullally, comedian Ken Marino and “Breaking Bad’s” Giancarlo Esposito, who plays a man who turns into a chihuahua when he’s ready to fight. He can turn back into a man “only when I’m not ready to fight, which is almost never.”

But when Episode 2 turns into one long poop joke — Axe Cop fights a “poop monster” named Dr. Doo-Doo in London, “where poop gets its power” — any hopes of this being smart, adult comedy gets flushed down the toilet.