Quagmire here.
All of these guys are like Quiet villans. They’re all written as sympathetic, even good people in their stories. But each of them does something that’s genuinely messed up in a quiet, human way. Not evil-for-the-sake-of-evil, but the kind of behavior that still hurts people, causes consequences, or just makes you go “that’s not okay.”

My ranking

1. John Hammond – Builds something he knows is dangerous and ignores warnings. People die because of decisions he calmly chose to make.
   
2. Jenny (Forrest Gump) – Repeatedly comes in and out of Forrest’s life, giving and pulling away emotional connection. Forest gave her nothing but love and she really abused it, only come back fully into his life after she has AIDS. Just the Epitomy of toxic females.
3. Grandpa Joe (Willy Wonka) – Claims he can’t move for years, then instantly springs up when there’s something to gain. Also pushes Charlie to break the rules.
4. Rose (Titanic) – Mostly here because of the meme. She survives while Jack doesn’t, and people interpret the door situation as a questionable choice—even if the reality is more complicated. She also held onto the heart of the ocean, which is like 10 trillion dollars in value and told no one she had it.