Time for a new proposal, this time, one of my favorite animated villains.
Scarface is a blue fox in White Deer Park, the second most powerful animal after the Great White Stag. But when Fox and the Farthing Wood animals arrive, Scarface takes an instant dislike to them, mainly Fox. After he is forced to give up some land to the Farthing Wood animals, he gets real pissed about it, going out of his way to try and make sure the animals die. This leads to him attacking and killing Mrs. Vole while on Farthing Wood land, breaking the rules set by the White Stag and almost leading to Fox taking the fall for it until Weasel rats him out.
Then Scarface, after learning Weasel saw him kill Mrs. Vole but not learning she told the others, bites her arm savagely and forces her to become his spy. When poachers begin preying on the White Deer, Scarface uses this as an opportunity to try and get Fox, who is working to drive out the poachers, killed for the sake of 'revenge.' What is Scarface taking revenge for? Why, his the death of his kids.
Specifically, the part where Fox and Vixen took the chickens they had nicked from a farmer who shot them. How dare they steal his food! That was his, not theirs! Sure, his kids are dead, but that's besides the point!
This attempt ends up failing and things are somewhat peaceful... until Fox and Vixen have cubs, which Scarface hates because he thinks they are better than his own. He says as much to his mate Lady Blue, while also stating his cubs have her "lily livered blood!" To get even, he murders Fox's daughter, Dreamer, leaving her body for her parents to find. Then he also kills Mrs. Hare in front of her family, just to be a spiteful bastard.
Fox cannot do anything because no one can prove Scarface did anything, sneaky bastard, so he tasks Adder with killing Scarface. Unfortunately, Adder kills the wrong fox, one of Scarface's sons, and for her troubles, Scarface bites off part of her tail, establishing a deep and mutual hatred for each other.
Scarface eventually leaves and after learning his mate Lady Blue was wounded in a savage fight with Vixen, uses that as an excuse to try and wipe out the Farthing Wood animals. This culminated in a fight between himself and Fox, with Fox trying to make Scarface vow to leave the Farthing Wood animals be if Fox wins... Scarface response with an evil chuckle.
After he is defeated, Fox spares his life as the other blue foxes won't follow him after such a humiliation, so Scarface slinks away to lick his wounds... and then kills Mrs. Rabbit, showing that he will never stop in his quest to destroy the Farthing Wood animals.
But Adder finally takes her revenge on Scarface before Fox and the others can, sinking her teeth into him and pumping him full of venom. As he lays dying, Scarface declares his line will avenge him... but in the end? They don't.
In terms of heinousness, Scarface has the highest body count in the series. Other animals kill for food, but not Scarface. He's killing for power and out of spite. Even in a series this grim, Scarface stands out.
In terms of redeeming qualities... his relationship with his family is interesting, as he will avenge his children's deaths, but this always ties back into his hatred of the Farthing Wood animals. When Adder kills his son, he only goes after her once Lady Blue tells him that there is an Adder among the Farthing Wood animals, not even considering it could have been any adder and not the one with the Farthing Wood animals.
Scarface uses the deaths of his kids and the attack on his mate as excuses to destroy the Farthing Wood animals, never showing any grief for any of this. At best, Scarface views his family as either his possession or extensions of himself. At worst, they are soldiers to die in his war on Fox. He is constantly abusive to them, even though his family clearly loves him. Lady Blue, his mate, mourns his death as does his son Ranger, but he never shows them any real love, only treating them as things he owns. At one point, Ranger, while trying to warn the Farthing Wood animals of Scarface's coming attack, admits his father would kill him if he found out he had gone behind his back and he clearly means it.
So yeah. Along with being a ruthless killer driven by spite, Scarface is an abusive father and husband who, as pointed out, only cares about others as things to be used for his purposes.
In the end, Scarface is an easy keep. He's also, again, one of the best animated villains I have ever seen. He's just such a bastard you cannot help but love him for it.