I wouldn't personally hate any of my characters. Maybe dislike them to the point where I wouldn't include them any longer in my story, but there's always a chance of putting them in a situation where I can change their personality or outlook on things and that way I wouldn't dislike them so much.
I have this character who I created in an attempts to fit into a fandom, so I made him more or less attractive and approachable. He consistently drew the wrong people to me.
I have a couple villains but one villain that I just introduce in my current novel, I hate him especially what role that I have eventually having him to do. While I always have a hard time writing villains, I feel that I improved in writing them so I guess I don't regret creating them because it brings me out of my comfort zone.
I have one character in a novel I'm slowly working on that kept evolving as the story evolved. He started as a love interest, then became a helpful side character, and finally...he's now the main villain. He kinda fell out of favor. I guess the opposite happened with him. I didn't hate him, but I was never particularly attached or felt too fondly of him. I eventually just made him a bad guy in a fit of rage, and then the rest of the story fell into place.
Maybe giving your character a new role would help? Start lightly pushing them in a new direction and see where it takes them.
Reading through my ideas from my teenage years is excruciating. When I was a teenager, I was a different person and created perfect, ‘pick me', not like other girls’ characters. The same stuff that made me almost completely stop reading the YA genre in the first place when I realised how toxic it is.
Yes, I have a few - and they came from my imagination so what does that make me. 
My most vile character is my MC’s uncle. He is next level - worse than my main antagonist to be honest.
I feel like I'll only end up in this situation if a bunch of people become Urien apologists and start insisting he "did nothing wrong." Right now, I hate Urien, but in a good way, like he's a very effective villain in that the readers, even those who admire his charisma and ambition, think he's an awful person and want to dump him in a muddy pond, so I don't regret making him.
I did used to work on a modestly well known game series (at least in RPGmaker circles) called Vacant Sky, where the creator genuinely did regret creating a certain supporting villain character called Weapon because the fans liked him so much for being a hot guy with a tragic past, in spite of the fact that he was an awful mass-murderer who enjoyed inflicting pain and suffering, and shipped him with the main character. I'd be pretty pissed if that happened, so I hope no matter how much we might see that Urien has sad feels or is lonely or that he's an orphan, that readers never forget he was 100% willing to let a demon eat a fourteen year old girl for calling him out.
I don't hate the characters I create, but I do find myself being biased with one or two to the point I think they're fucking amazing. I'm particularly fond of magnificent bastards, which is why I take care not to make them flawless or fearless in order not to make them cheap.
I hate obnoxious cocky types, which is why I tend to avoid having any in my stories altogether.
I get you. Yeah I had to do that for some of my characters before, I tried to incorporate some of their habits and story into other characters.
@BitterBadger I guess hate is a strong word for a character you creates. lol
@cursedbeast Oh no! That's not good! D:
@NellieVP318 That's good to hear. I am the opposite. I actually like writing villains.
@likhoradka Oh! That's a good idea to make a character into a villain. Idk I might just write them out or keep the to a minimum.
@Geek_Aflame My gosh! I cringe at my old stuff too! It's so hard to look at sometimes! I completely understand. lol
@Legendofgenii great I don't feel alone in this. lol! but the uncle way worse than the main villain. wow. He must be a next level horrible character.
@darthmongoose Oh man that must have been rough for the creator. Cool you worked on a game too!
@nickolaidas Yeah I have this issue too. being attached to characters and making them as fleshed out as humanly possible.
I had a character who exasperated me, but hate? No, not really. I am usually curious about my chars to the end of their journey
I plan to create such a hateful character i would hate but i would find a way to write him with my writer that i would end up liking him.
But right now in my comic i already have a character i hate but he's a minor character so I dont have to draw him much.
I wont regret creating them, its part of the story
I never really understood the concept of hating your own character, let alone regret creating them. If you don't like the character and think they are pointless to the story, delete them and replace them. It's that simple. If they are important for the story, then why would I hate them? They are a tool for my story to be more entertaining. If anything, I would be the hypocrite for hating them and quite frankly look silly while doing so. They're characters... I know how to love my main characters as I see them like my own children, but even the antagonists in my story are still just people I made up in my mind. I try my best to make them interesting and not just annoying characters to write. That's all there is to it for me honestly.
And as a side note, if YOU hate your own character, then how are your readers supposed to like them? I would suggest giving it some more thought. What is it that makes you not like them? Maybe if you figure out the answer, you could prevent your own readers from having the same feelings as you.
Hm, I guess you could say I disliked the characters that I ultimately ended up removing from their respective stories. But that was less of an active hatred and more that the characters weren't developed well enough and weren't really contributing to the plot.
There was one character that WAS too important to remove from the story that I ended up disliking. She was meant to be a kindly, motherly-type character, but it got to the point where she was SO nice that it irritated me. But I never finished the story anyway, so it's kind of a moot point. 
No, I don’t regret any of my creations. Even the evil ones. They all serve a purpose, after all! If you dislike one of your ocs you certainly don’t have to draw them anymore.
Hm, I don't hate the chara, but he got useless. My main chara has a voice in his head which I wanted to use for some fun and dramatic scenes... But yeah, now, after some years working on my story, he feels kinda off and out of place. I'm not sure, if I should just delete the pages, this "voice" is in...
Other than him, I like everyone of my charas, even the plain background-characters.
What you're describing, and please take my words with a grain of salt, sounds closer to burnout than actually hating a character. Sometimes, when I overexpose myself to certain ideas, or characters, or writings, I get so sick and tired of looking at them that I start to dislike them. That's why I think it's so important to take frequent breaks.
Speaking personally, I can't say I've ever written a character I hated that wasn't intentionally supposed to be hated. And even then, I usually take a lot of pride in my dastardly villains. The more reviled they are, the happier I am. It could be you don't feel like your character is serving the purpose you originally designed them for anymore. Again, I'm just offering suggestions. But if that's the case, I would suggest either finding a way to revitilize that character or, failing that, give them an end that's both satisfying and brings closure.
I can't really say I hate any of my characters. But I've had ones that just don't work for what I wanted them for anymore. And since I had to have put something I like in there to make the character in the first place I'd rather not just drop them and be done with it. Instead break them down for spare 'parts' Just take what traits you do like and recycle them into a new character lol.
Jamie McCollough of "The Depths".
One dimensional, boring, nonredeemable, and just pure evil.
We really blew it with that guy. Usually a villain should have something a reader will like.
This was bad planning.
Happily, he's drowned now and we have a much better storyline, and much greater, more awesome evil.
