- The glorious return of the pipe joke.
Clover: Give me a "P"!
Tenmyouji: Give me an "I"!
Sigma: What is wrong with you?!
- Despite being a Killer Rabbit, Zero III has some rather amusing lines.
- "No, I won't wait. I don't like waiting. I waited once, and some half-witted reptile got the better of me because of it. After that I learned to make sure to value my time."
- Before entering one of the puzzle rooms, Sigma attempts to get Clover and Luna to pull on a lever using some rather suggestive dialogue. Eventually, Clover gets fed up.
Sigma: Clover, try pulling that lever.
Clover: Why do I have to do it?
Sigma: It might be dangerous. I was hoping you could just wrap your hands around it and give it a good jerk. It is kinda big, but I'm sure you can handle it. Just...be gentle.
Clover: Uh... This doesn't seem like appropriate workplace behaviour. You're kinda grossing me out.
Sigma: I know you probably still think of yourself as just a girl, but you've become a woman some-
Clover: You're not making it any better! Why don't you do it?!
Sigma: If you can't take it, then maybe Luna can. Have you done this before? You just start at the base and work your way up, then give it a good tug once you get to the top.
Clover: What is wrong with you?! If you're so desperate to give that lever a good time why don't you do it yourself! Just leave me and Luna out of your sick fantasies, you creep!
Sigma: Hmph. Fine. But I won't like it.
Luna: One of the doors opened. Hmm, we might as well go through it.
Sigma: Maybe we should try flipping it one more time, though... I think you could actually manage with just one hand, Clover. Just do it real fast, it'll only take one second. Just up and down once...
Clover: Ugh. You are disgusting.
- In the Archives, by examining a desk again after getting the items off of it, Clover opts to crawl under the desk and check there to be sure. This gives Sigma his only successful pervy moment in the game.
- During the pantry if you fail to solve a puzzle too many times, Clover notes that Sigma is having a hard time, only for him to rudely ask her for the answer. She decides not to help him until he apologizes properly.
Clover: Say it!
Sigma: C-Clover-chan is... hella moe...
Sigma: Clover-chan is hella moe!
Clover: Eeeeeee! Oh, you're embarrassing meeee! He he he.
Alice: What in God's name is wrong with you...
- Sigma using logic to determine how he ended up in the game.
"Had I started a fight with a frightening and mysterious new religion? No... Had I hacked into some terrorist group's server? No... Had I witnessed an assassination? No... Had I gotten wasted and had a one night stand with the mistress of a prominent politician? Well, yes... But it was just the one time...And she was the one who went after me..."
- It gets better when you realize that Sigma proceeds to do all of these things over the course of the game.
- K on the kiddie ride in the Rec Room, and Sigma and Alice's reactions.
K: Eeeeeeeeeee he he he he! Look at me go!
Alice: I... I can't watch this...
Sigma: There is no god...
- Tenmyouji voices what anyone who played 999 was thinking upon seeing a room labeled 'Q':
Tenmyouji: Alright, now someone's just being a smartass.
- The description of the jellyfish puzzle in the treatment room ends with "If you move one of the yellow jellyfish to the hole instead, you are a failure and we are very disappointed in you"
- Going through the green door with Luna and Alice leads to a number of these, especially when examining the robot with the boxer shorts.
Sigma: This one is wearing boxers...
Alice: Y-Yeah, looks like it...
Luna: Why would a robot be wearing underwear?
Sigma: Maybe he's, uh, hiding something.
Luna: Hiding what, though?
Luna: Like a diary or something?
Sigma: Why the hell would you hide a diary in your crotch?!
- Not to mention Alice's...enthusiasm in removing the shorts to check if it has a 'hose'.
Alice: Remove these shorts of obfuscation and let us gaze upon it - this so-called "hose"!
- In that same room, try examining the cluttered desk in the back, multiple times. The sheer amount of random things Sigma does to try and find something useful is hilarious, capping it off with Alice needing to slap Sigma so that he doesn't eat something.
- Two Words: COCKNEY. ROBOT. Or Kansai Robot.
- Dealing with the Schrödinger's Gun aspects of the game, at one point Sigma is taken aback that in one route Alice betrays and in another, she allies, depending on what Sigma chose. He goes over all the aspects of why this shouldn't have happened, when...
Sigma: No, wait... wait! Wait wait wait wait wait! Why the fuck was I talking so casually about going back in time?!
- Sigma's reactions to a lot of the puzzles, especially the difficult ones.
Sigma: I JUST SOLVED THE SHIT OUT OF THIS PUZZLE!
- This is funnier when you remember Troy Baker said a similar line in another game.
- Pretty much everything Sigma says becomes this retroactively when you learn that Sigma is in his 67-year-old body. It's funny enough imagining Troy Baker saying Sigma's lines, but try to imagine the voice of Jamieson Freaking Price spewing cat puns!
- Dio offers an invite to K for a drink in the lounge. K is not impressed.
Dio: You wanna tag along K?
K: Are you making fun of me? I find it rather hard to drink with this mask on.
Dio: Oh, right, of course. My bad.
- What makes this funnier is that Dio's response to K implies that he genuinely forgot that K is wearing a mask, and wasn't actually making a bad joke at K's expense.
- The player's realization, post-reveal, that the flowers on Luna's dress resemble the Windows logo. It Makes Sense in Context.
- Going to the laboratory with Dio and Clover prompts the latter to make go on a tirade of puns, prompting Visible Silence from both Dio and Sigma. After Clover pats herself on the back for her humor skills:
Dio: Sigma, please, let me give her a smack.
Sigma: I wouldn't do that. What if it only makes her worse?
- Clover's insistence that the jellyfish are aliens. And then naming the purple one "Ellen" after fishing it out of the tank.