Tentacles is a good "realistic" fiction. It depends on how you look at it. There are arguments both ways that can be valid, but I will list this as realistic fiction. I think that this book gives a good look into cryptids. I think that this book is a really good read, and that it is a well known book.
Marty and his friend are trying to find the giant squid. That's the best part of the book. I think that people should read this book if they are a bit bored, or just looking for a good book to pass the time. I have read Cryptid Hunters, so son't worry there. I really recommend this book.