Books for a quirky 7 year old?

Hi everyone! My 7 year old nephew is going to live with me for a month this summer while his dad is in rehab. This kid has been through a lot already in his short life, and he is remarkably well adjusted and happy despite all of it. My partner and I are currently prepping for his arrival, and I could use some help. He is a voracious, advanced reader with a love of both comedy and horror. I want to put together a mini library for him while he’s here, and am overwhelmed by possibilities. I would love your recommendations for kid and YA books that he might enjoy. I am open to any genres, including non fiction. He still likes to be read to, but also enjoys reading on his own, so story books and chapter books are both appropriate. This kid means the world to me, so I appreciate any assistance in giving him the best summer vacay ever!

EDIT: I am touched and overwhelmed by the response this post has gotten. I gave up responding because so many of you commented with recommendations I can’t keep up! I am working through the responses and creating a list of options for my little guy. It has been so great to learn about the books that you loved as a kid, the books you read to your own kids, and the books teachers have in their classrooms. As I mentioned to a couple of you, reading was my escape from my own messed up childhood, and I believe in the power of words and art to heal. Posting this has shown me how special this community is, and your kindess has truly inspired me. Thank you, thank you, THANK YOU for taking the time to share your love of reading with me and my special little dude. Much love to all of you!