Family, Friends and Pets I've Written into my Books
I've actually written more people I hate or have pissed me off into my books than family or friends. It's a very cathartic things, to take someone who has ticked you off, and kill them off in a spectacularly wonderful gruesome way. I know, too many adjectives, but I've used this cheap therapy method often. I think the most notorious is the name Daniel, who used to be an old boss. He was such an awful man that I used his name as the bad guy in about four books. My friend, Lark, told me to stop using it because she knew who the bad guy was immediately.
I've also used some of my family and friends in my stories, we well. My friend Lark showed up in various incantations in my early novels. The "best friend" was always a variant of her name. My mother showed up in my second book, "An Innocent Heart". My ex's were the names of my heroes in the Forgotten Rebels MC series. And recently, I used my soon-to-be husband as the inspiration for the hero in "The Last DiLuca" (featured in the Evernight anthology "Lawless").
I don't think I've written any pets in. I could be wrong but I don't have pets so I don't tend to put them in my books.
I have to believe that many authors do the same thing. I believe it's a natural reaction to the environment around us. People who piss us off become fodder in the next book. Can you think of any other profession that allows us to kill off our bosses and not get arrested?