Whenever I think about an animal that I hate, I just remember about that thread about why Koalas are terrible animals. Not only because it is funny, but because I think koalas are just... ugly and disturbing, I rather deal with a plushie or animated version of them.
I agree 100% percent // TW: A lot of curses and insults but worthy if you don't have a soul just like me
I agree with mosquitoes, but another contender for me would be tapeworms. They scare the living daylights out of me. And just the thought of this...thing living inside your system is just–
Wasps also because I adore bees and designed our garden for bees specifically. Its incredibly chill sitting there watching them do their thing over summer. They even snooze on the flowers.
I´m scared of dogs because I have been bitten by dogs several times.
Hate is a too strong word.
I dislike insects like moths and butterflys. People love butterflys, I don´t
Tough question if I have to pick just one, because I hate ticks, spiders, wasps, mosquitos and slugs a lot and almost equally.
Ticks carry deadly or life-changing diseases (if left untreated) and are hard to spot until it's too late. Plus, together with spiders, they look very disturbing. Those crooked and long legs just... shudders
I hate wasps and mosquitos for the same reasons @darthmongoose and @NickRowler mentioned.
Invasive species of slugs multiply in gazillions and they eat everything and climb everywhere and hide everywhere. They're gonna take over the world one day... 
flies and moths
most bugs make me scream but with those two, I'll just go apeshit.
i was attacked by horseflies twice when I was a kid, Both times on the face. I also get really fucking squeamish around them cause I know then they're rubbing their little hands together they're getting fecal matter on whatever they just landed on. And people will sometimes just let that happen, then eat the food regardless. I can't, it makes me nauseous.
And when I lived with my grandmother there was a moth infestation (that my sister caused, there were maggots in her room and everything it was fucking disgusting) and moths would just be eating my clothes and even my physical art. I don't understand why people think they're cute, they're horrible evil creatures that serve no purpose.
Not going to do armchair psychology or anything, but have you looked into possible phobias per chance? :o I brought up my mother's phobia of geckos with my therapist one time and she mentioned a lot of people don't look into it even though a lot of reptile aversions are tied to other anxieties - like for example, that my mom associates geckos with some rough living conditions when she was younger so strongly, it's the same as being back there.
unless you actually had bad experiences with reptiles or just plain don't like them, then disregard my entire post 
Squids. Wtf are they. Like octopuses are cute. Squids? Just hellish sea abominations. Oh and there's giant ones. My friend worked at a sushi shop and she said that they don't bother her because she used to scoop out their eyes.
Leeches are really weird. Like WHYYYYYY. They suck your blood. And then there's people who put girly ribbons on them and keep them as pets.
Uhhhh let's see... I want to kill every hornet on this planet.
Cats... I originally hated (allergies), but my sister got a hypoallergenic one and now I'm obsesed with her. I got dem parasites.
I hate how Toads have babies coming out of their backs. That stuff is NASTY.
Annnnd finally while I don't hate pugs, it sucks that we made them that way. I kinda feel... sad... looking at them.
Basically anything that makes me throw-up I want nothing to do with.
@darthmongoose Btw (and this is a true story when I was like... 7). There was a wasp nest inside this lamppost and my cousin would just play around by having us look inside the nest before we just run away from the wasps. The dude was super buff so he would just grab little itty bitty me and we just ran while they came after us. I just realized the consequences of that little game lmao. It flew into your mouth, I could've gotten stung in the EYE.
But it didn't happen so... good times :v
Flies
They literally have no reason to exist other than to eat dead shit or just breed and spawn into places for no reason and to PISS YOU OFF
Bruh for some reason I can handle spiders and roaches. I still hate them and will avoid them at all costs, but they're not the worst.
but TERMITES! I hate them! I hate them with a passion. That squiggly thing, and who gave them wings too??
They often show up at dawn, and I'll stop any activity and run to my safehouse (my room). 
Mosquitoes are proofs that Satan does exist.
And spiders... ranting on spiders is that they're the ones that decide to crawl in our spaces like at work in a warehouse. I mean, they SEE YOU and decide to crawl down on you anyway and there would be a potential you want to swat them and get yourself bit... it's not our fault. It's not like we decide to crawl in their homes... we just leave them alone so we won't get bit.
I find them visually disgusting. I can feel my skin crawl when I see a reptile, even in a picture. I really, really dislike them. I think I have a very "touch" oriented memory sensory input and I can imagine the slimy skin and it freaks me out just thinking about it.
I don't think I had bad experiences related to reptiles, I never liked them since I have memory. (And I remember a lot of my younger years)
