I never had any negative comments in the 100 or so I've had, all positive and interaction.
I did however once fuck up a continuity aspect, and was promptly corrected xD (politely though)
Didn't have any mean comments on here so far. I've got some weird ones on dA and two straight up hateful by the same person on my Facebook page, but that's another story. XD
Unfortunately, the meanest comments I've ever got were from my parents and ex-friends. 
The most memorable of them:
- When I was a kid, I had a task to draw the animal (or something like that) in the drawing school. I drew the cat mother with taps instead of nipples. Nearby I drew kittens, who opened that taps and filled small cups with cat's milk. I was proud that I invented so unusual cat and couldn't wait to show it to my mother...
L(° O °L)
When I did it, she made a face like I'd done something indecent. She said that cat with taps which give milk is the stupid and absurd concept, and she wonder how it even came into my mind. I started to cry, and drawing teacher came to my mother and said something like: "It is bad to say such a bad thing to your children. You are ruinning her self-esteem. Be positive!". After that my mother came to me and said something like "um... wel... ok... maybe it is not so bad... you just wanted to be original, right?". I stopped to cry but remained sad, because I had heard her talk with that teacher and understood that she is probably not sincere. - When I was teen, I wrote the very short romantic story. It did not contain sex, but it contained kiss. I showed it to my mother, and she laughed and said something like "Do you have itches between your legs due puberty or what? You'd better go make something useful". Of course, I cried and ripped the paper with the story into pieces (I was very sensitive teen). ¯_(ツ)_/¯
- When I studied in the university, I had very sad and desperate mood during exam sessions, because they always were hard to me. At one of such days, I took the pen and the paper and drew the picture of the dude who was standing in the dark corner and pointing the gun to his own head with a scary smile. Frightening shadows were visible on the walls near him. I tried very hard and liked this drawing, so I decided to show it to other student girl who was my friend those times.
She looked at this picture with a face like I'd done something indecent (I hate so much when people look like this at me and at things which I do!). Then she asked, what does this mean. I said that this dude is surrounded by enemies, so he decided to kill himself to not being catched. It was the idea of the picture. She said: "But it is... horrible. Why don't you draw something positive and kind? Why do you want to draw something like... that? It is not normal!" with the same expression on her face. Of course, I destroyed my picture after that. - Later, I started to write stories and publish them in the social network to show them to my friends. And one person who knew me and read those stories, tried hard to find pointers to my complexes in them. When I wrote about domineering and cruel women, he asked if I want to be BDSM mistress. When I wrote about alien, who had an "evil" moral, cardinally different from humans moral, he said mockingly that I read Nietzsche too much. When I wrote about the person who had the conflict with society and whom nobody understood, he said that I didn't grow up and I am still a teen who want to be not like everyone else, etc.
It is cool that people here are not like that. 
All the coments i got are extremely positive, so is hard to tell which one would be the "meanest"
Maybe something among the lines of "i like this"???
About actual mean comments, on a short random video i made, a person posted something like "get a life".....and posted that comment twice. I just ignored it.
That insult is extremely generic. Probably he didn`t even read....I guess some people try to vent up their deep seated emotional frustrations in online forums by randomly insulting something.....
Brutally honest reviews hurt more than this, but they're at least helpful (･ัω･ั)
Ah well, what can ya do
Dang, man! It sounds like you have all the proper fuel to be a great writer. 
Man, I remember drawing a lot of screwed up stuff in high-school as well. I destroyed most of it, because, looking back, it probably came from a fairly disturbed place. I never shared any of them though. I usually only showed my happier drawings.
I have to see this cat with tap nipples though. It sounds like you were way ahead of your time.
I have to second @storytimebiondi you were way ahead of your time. Tap-cat would be a hit nowadays.
must..... resist.... the urge to draw fanart of her! 
Darker stories/art are not everyone`s cup of tea, you were just aiming at the wrong audience.
Is frustrating when people close to you dont get your work.
Some people try to read TOO MUCH between lines. Nobody likes people randomly analizing them.
Clearly this isn't hate nor mean but sure is confusing for me haha. Someone told me to watch more drawing tutorials. The person further added that it's not because my art is bad, just unique. I totally accepted the first statement because definitely, I am still trying to learn. But the next sentence just left me so confused hahaha.
Would someone recommend me some great drawing vids please? 
That would be Awesome Possum!
"Sometimes people are so disrespectfull to inanimate objects........"
"They may not have eyes, but they still cry on the inside......."
The comment was in my native language, so it translates roughly to:
"My hatred for this comic grows with each page, I get sick in my stomach when I see an update in my notifications"
...but nobody is forcing you to read it???
Well, now I get sick in my stomach from laughing, because I imagine how that dude is making an angry face every time when receiving notification, and then suffering, reading the comics through pain and ire
@spicy_sweets Geeeeeez. 
At least it seems like they weren't singling you out.
As for the meanest comment I've received online... I can't think of any that were hateful, but I have had one person give me a critique that had little to do with the story. It was in response to a thread on the WT forums. Looking at their feed, I realized this person was copying and pasting the same feedback randomly on peoples' stories just to get the "payment" (they were asking for people to check out their story in return).
It was a LOT of comments on two separate occasions by two different people, one of them was on dA, another was on a site my comic was uploaded to without my permission (A reader informed me that they had first encountered/read my comic on a porn site)
Raven Wolf was the comic that was re-upload, and there was a reader that would basically leave horrible insulting comments about both me and the comic while constantly starting fights with people that liked the comic. At one point someone asked them why they are reading the comic when they clearly hate it so much, and to go do something else that they might enjoy more, and their response was "I want to watch the artist inevitably crash and burn."
The comic that I got harassed for on dA was No Future and this dude would leave... really really really long paragraph filled hate messages on random pages that I posted, he would also fight other people leaving comments. He was basically pissed I was updating this comic more often than I was updating Raven Wolf. Additionally, every time someone gave him a bad review on one of his dA uploads he blamed it on me for 'sending the trolls after him' he also started demanding that I write a public apology to him for 'convincing my readers to attack him' which I never did. (even when I looked at the comments in question they were all left by people that I had never heard of that do not follow me)
Anyway, the comment that bugged me the most out of the many many many many hate filled rants this guy left on my pages was basically the comment he left when he found out I was sick and thus, why I was working on a comic about a character facing his death. This dude got livid, and basically left a long ass hate filled message directed at me that contained the comment "So you're basically going to die, wow, thanks for wasting my time. How dare you get me invested in a comic that might never be finished because you might die." Which of course was followed up by a long argument on how I should have never started a comic if I knew I was sick because doing so means I don't care about my readers.
@Kura Wow 
I can't believe some people.