What is "dark" humor? I'm sure there's a formal definition, but for me dark humor is often irreverent, against society's accepted behaviors, perhaps a touch ironic, perhaps a touch morbid, and almost always makes you want to say "What? Why am I laughing that was terrible!"
Personally, I love it, but pull up "I Want My Hat Back" on Amazon and hit the one star reviews and you will hear from a slew of people who do not. This post is not for them. However if you like a good bit of dark humor read on as I have listed out some of my favorite picture books that feature darker humor.
Spoiler Alert for a lot of these. If you don't want them to be spoiled take note of the titles and read no more.
I will rate the following books based on my personal opinions - Dark Humor Rating will be on how DARK the dark humor and how much the author leaned into it.
Then it will have a label: E for a character gets Eaten; I for Irreverent; or M for a character gets Murdered.
I Want My Hat Back (and the whole hat series) by Jon Klassen
Dark Humor Rating - 10/10; E

This was the first dark humor picture book I ever read and it was with my kids for the first time which was really fantastic because we got to experience the shock together. A calm and kind bear is on a mission to find his hat. He finds it. Someone gets eaten.
2. The Book That Eats People by John Perry
Dark Humor Rating - 10/10; E & I
It's self explanatory here, but this book eats people and the nonchalant way it goes about it is just hilarious.
3. Eat Pete by Michael Rex
Dark Humor Rating - 6/10; E

Once again we have a character that gets eaten though, to be fair the monster does try to NOT eat Pete… this one has a sweet ending that isn’t as dark.
4. All My Friends are Dead by Avery Monsen & John Jory
Dark Humor Rating 10/10; I
Some folks might not consider this a kids book because it is DARK. I’m not sure the plot really needs explaining.
5. The Bridge by Eva Lindstrom
Dark Humor Rating 9/10; I
A pig takes a detour and ends up at the wolves’ house. Lots of hints of murder in the background/twist ending.
6. Bethan Woollvin’s fairytale retellings: Little Red, Hansel & Gretel, & Rapunzel
Dark Humor Rating 10/10; M & E
While all of these have a touch of murder in them, the reader knows that the victims (an evil witch/a wolf/bratty kids) are just getting what’s coming to them. Hilarious / not to be missed.
7. I’m the Biggest Thing in the Ocean by Kevin Sherry
Dark Humor Rating 7/10; E
Go on, be an arrogant squid or whatever, see where that gets you.
8. Not Now Bernard! By David McKee
Dark Humor Rating 10/10; E
Parents are too busy to notice that Bernard has been eaten. No resolution or apologies. Hilarious.
9. Wolves by Emily Gravett
Dark Humor Rating 5/10; E

I didn’t rate this one very high in dark humor because the author sort of backtracks and gives you an alternate happy ending where the rabbit doesn’t get eaten by the wolf. Personally, I would have loved an alternate ending where the rabbit ate the wolf instead.
10. Somewhere in the Bayou by Jarrett Pumphrey and Jerome Pumphrey
Dark Humor Rating 10/10; E

Trying to cross a body of water with a crocodile in it can be dangerous work. Remember to be polite.
11. The Unexpected Crocodile by Kim Kane
Dark Humor Rating 7/10; E
A crocodile turns up for dinner and eats the very rude guests. No one seems to care. This would have had a higher rating but the author sort of hints that it may or may not have happened.
12. Duckworth the Difficult Child by Michael B. Sussman
Dark Humor Rating 5/10; E
More uncaring parents star in this book where Duckworth gets eaten by a snake. In the end, he is free so not as high of a dark rating.
13. Snack Attack by Terry Border
Dark Humor Rating 7/10; E
Snacks are free to explore the kitchen, and have thwarted plans to be eaten. Or have they? A little expected.
14. Tadpole’s Promise by Jeannie Willis
Dark Humor Rating 10/10; E & I
A love story gone so very wrong. No apologies. 10/10.
15. Fluffy McWhiskers Cuteness Explosion by Stephen Martin
Dark Humor Rating 10/10; M

Fluffy McWhiskers is so cute, people, animals, etc. explode. Ends with LOTs of well..cuteness...
Some adults might think that kids can’t handle dark humor, or shouldn’t be introduced to it, or that it isn’t appropriate. They are allowed to think that. What I know is that my kids, and many other kids we know - LOVE IT. I think kids understand that the world isn’t all sunshine and rainbows and sometimes a bit of darkness can still be fun.

I Just Ate My Friend by Heidi McKinnon is brilliant dark humor! It’s an oh-you-can’t-do-that story, but she did and it’s perfect.