1. Clay Puppington: Yes. This asshole of a dad. I admit that I had neglected to watch Moral Orel when it aired on Adult Swim, namely because it seemed to be a bad parody of clay-animated shows such as Davey and Goliath. I have since appreciated the series for delving into the darkness of organized religion as well as the utter hypocrisy of its believers. Clay to me is the epitome of all that a father should not be. He is a self-centered, cynical, pathetic excuse for a human being. Even when we have some semblance of sympathy for Clay, he immediately pitches that off of his shoulder and returns to being an ass. In season one, he was more of the parody of the upright patriarch who had his moments of being played for laughs. Come the finale for season two, however, and that all comes to a screeching stop. Clay decides to take Orel out to the woods to hunt, only to find himself growing increasingly annoyed by Orel's good nature. This climaxes to Clay shooting his son in the leg, ripping off a sleeve of Orel's special shirt, and then drinking the medical alcohol that places him in a coma for a while. Orel had no way of getting to the hospital, and now limps because of it. While Clay would claim that he had no recollection of shooting his son, in one of the episodes of season 3, he proudly brags about how glad he was to have shot Orel. Clay brings disgust and misery to everyone around him all as his way of trying to have some attention, even if it is unpleasant.
2. Fire Lord Ozai: What is there to say? He disliked Zuko because of how he wasn't a prodigy like his sister; he nearly burns his son's face off before banishing him all because he had spoken out of term during a conference; he treats his daughter Azula as nothing more than a tool which explains her sadistic behavior; in the comics, he even threatens Ursa that if she were to take the kids with her into exile, he would hunt all three down and kill them.
3. Peter Griffin: Once a lovable idiot, now a sociopathic prick. In one episode, Peter threw an unconscious Stewie underneath Lois's car, thus making her accidentally run over him. He even admits to dropping his kids several times when they were babies. He once injected Stewie with steroids; he tried to marry Chris in order to inherit money that Carter gave to Chris for his assistance; he asks God in one episode to erase Meg from existence. Even when the world was allegedly ending, Peter admits that he finds his children boring and doesn't wish to have anything to do with them. He tried to brand Meg like a cow. He farts in Meg's face every time he got. There are of course more actions he had done towards his kids that could be summed up with a brief laundry list but we'd be here all day.
4. Aku: When your name literally means "evil" in Japanese, this is warranted. In season 5, Aku had closed himself off from the world because he believed that since he destroyed every time portal, his hated enemy Samurai Jack was a sure goner. Unfortunately because he had whisked Jack far into the future, he unintentionally made Jack immortal. Somewhere between those 50 years, Aku visits the Daughters of Aku, a cult revolved around worshiping him. Pleased by this, Aku decides to humor them and gives them some of his essence....which the High Priestess then drinks. And so, Aku became a daddy. Upon realizing that Aishi was his daughter, Aku turns her against Jack and even tries to force her to murder the one she loved. He even transforms her into a miniature version of himself.
5. Mr. Northwest: One of those rich pricks. He abuses Pacifica by making it to where she would obey his commands through the use of a bell. Or when Weirdmageddon was brought to Gravity Falls, he has the audacity to try to find favor with Bill by offering his service. While Bill is a monster, we could probably all agree that him shuffling Preston's face orifices was the only good thing that he had done.
6. Shou Tucker: The Sewing-Life Alchemist. He seemed to be an okay fellow at first, but then we learn that his license was about to expire. And so he did the unspeakable by stitching his own daughter to her pet dog, creating a chimera that can speak, but is in a state of constant pain. Worse, he even tries to deflect any sort of responsibility for it, viewing it instead as progress.
7. Judge Claude Frollo: Well, more of a case where the child is adopted, but it still counts. For starters, Frollo murders Quasimodo's biological mother before trying to drown him when he was a baby. He subjects Quasimodo to years of psychological and emotional abuse - feeding him lies about the world and that he was ugly - and then tries to kill him towards the end.