The joke is the gap between what zombies are supposed to be and what these ones actually want from you. They're grotesque little creatures that move wrong and smell bad, but they're also desperately, pathetically trying to be cute. The comedy lives entirely in that collision, and it never lets go of it for even a second. A two-episode sprint that knows exactly what it is and executes it with zero apology. If the premise makes you laugh immediately, this thing was built for you.
Zombie-kun is a zombie boy, and his short gag comedy is made for young children. He is meant to be silly rather than scary, and most of the laughs come from the strange things his body can do. He might pull out his stomach and blow it up to use as a pillow, or take off soaked body parts, squeeze the water out and stick them back on with a glue stick. Alongside Isamu, his closest human friend, he means to do good but keeps falling apart, quite literally. The art stays cute and cartoony so nothing gets too gruesome. The release is a two-episode ONA from 2017.