I don't have an exhaustive list of Zoro's quotes, so until someone comes up with such a list, I'll give you the ones I could find googling this problem. Keep in mind that these are translations and he might have said it differently in Japanese. Have fun reading.
His most recent one liner on Dressrosa is:
Over the 9 mountains and 8 seas... Throughout the world itself... There is nothing I cannot cut.
The quote you were looking for when fighting Monet is:
You've underestimated me, snow woman. When you thought you couldn't beat me, you should have run. Of course, there are things that I don't wanna cut. But... let me ask you something. Have you ever seen a fierce animal you were sure would never bite? Because I haven't.
You can find 29 quotes on less-real. They don't say when he said them though.
- If I die here, then I'm a man that could only make it this far.
- You need to accept the fact that you're not the best and have all the will to strive to be better than anyone you face.
- Bring on the hardship. It's preferred in a path of carnage.
- Either in belief or doubt, if I lean to one of these sides, my reaction time will be dulled if my heart thinks the opposite of what I choose.
- I don't care what the society says. I've regretted doing anything. I will survive and do what I want to.
- You want to kill me? You couldn't even kill my boredom!
- You sure can talk the talk, but you're not quite ready to walk the walk. Time's up, it's my turn.
- When the world shoves you around, you just gotta stand up and shove back. It's not like somebody's gonna save you if you start babbling excuses.
- So, are you stupid enough to fall for such a stupid trap that such stupid people set up?
- I'm a pirate hunter.
- A wound that'd make an ordinary man unconscious... I won't lose to it. A wound that would kill an ordinary person... I won't lose to it! To face one who is extraordinary, Hawk Eyes... I can't allow myself to be ordinary!
- There should be a limit to how similar a couple looks like.
- When I decided to follow my dream, I had already discarded my life.
- If you kill yourself, I'll kill you.
- Well, how about this. My "luck" versus this thing's "curse". Wanna see what's stronger..? If I lose, then I'm just that much of a man anyways...
- There is someone that I must meet again. And until that day...not even Death itself can take my life away!
- I don't know. I'm not sure why myself. But if I were to take even one step back, I believe that all those important oaths, promises and many other deals 'til now, will all go to waste and I'll never be able to return before you, ever again.
- So what if you're a girl.
- If I can't even protect my captain's dream, then whatever ambition I have is nothing but talk...
- When you decided to go to the sea, it was your own decision. Whatever happens to you on the sea, it depends on what you've done! Don't blame others!!
- You'll never understand...your swords will never be as heavy as mine!
- If you do anything that would cause me to abandon my ambitions... You will end your own life on my sword!
- Fine! I'd rather be a pirate than die here!
- I am always serious.
- I do things my own way! So don't give me any lip about it!
- I'm going to be the world's greatest swordsman! All I have left is my destiny! My name may be infamous...but it's gonna shake the world!!!
- If you die, I'll kill you!
- Bring on the hardship. It's preferred in a path of carnage.
More quotes can be read on animequotes.
- There is someone that I must meet again. And until that day… not even Death himself can take my life away!
- Well, how about this. My “luck” versus this thing’s “curse”… wanna see what’s stronger…? If I lose, then I’m just that much of a man anyways…
There is also wikiquote, which has a compilation of quotes, phrases, dialogues from One Piece. You could search for Zoro in the page for more dialogue from him, but I'll stick to his single quotes here.
- I will... I will never... LOSE AGAIN! Until I defeat him [Mihawk] and become the world's greatest swordsman, I'll never be defeated by anyone!
- This is the burden of a captain, you can't doubt yourself. In times like these if you lose your confidence, then who can we have faith in?
- When the world shoves you around, you've just gotta stand up and shove back. It isn't like you can do anything just by giving excuses. If I die, then I am just a man who can only make it this far.
- I'll get strong, stronger than she[Kuina] ever was, you hear me! Strong enough that my name reaches up to the heavens! I am going to be the world's greatest swordsman. I promised her... I promised.. I did...
I tried to weed out the doubles, but forgive me if I put the same quote more than once.
You can read more one liners of One Piece on reddit, but they aren't all Zoro's.