All Of Us Are Dead has its fair share of lighthearted moments that help ease tension in between intense and horrifying scenes.

As with all moments pages, Spoilers Off!

General

On-jo kicking Cheong-san behind his leg whenever he ticks her off.
Ho-Cheol keeps bringing up how he studied at Seoul University whenever he’s trying to convince Jae-ik that he’s making the smarter decisions.
Dae-su being the butt of fat jokes pretty much every episode, though YMMV.

Episode 1

On-jo asks Cheong-san on which side should her hair cover her ear. His response after Eating the Eye Candy? "Get lost". On-jo promptly kicks him in the back of his leg, making him wince and moan in pain for quite a long time.
After Cheong-san wins his race with On-jo to see who gets to be the other one’s gopher, she shows him her finger wrapped with a band-aid due to getting hurt while making breakfast. He simply drops his bag on her arm for her to carry.
The scene where students are rushing to get inside the campus before they get recorded as late.
- For starters, the crowd of students running late is comically large.
- Gyeong-su jumps over the gate of a wealthy apartment and slaps Na-yeon along the way.

On-jo uses a fire extinguisher to blind zombies. It becomes a Brick Joke when Dae-su enters the classroom covered in the white powder.
When the class goes silent, Joon-yeong is lying against the door. He fearfully slides down the door as a zombie appears outside the window.

As Su-hyeok jumps over to Cheong-san to kick off the zombified student girl grabbing the latter's leg, he naturally holds the latter's body tight (as Cheong-san is hanging on the makeshift ladder made from a fire hose rope), giving some really funny subtext-filled dialogues. Cheong-san is obviously uncomfortable while Su-hyeok keeps poking fun at it.
- Even better, there is a very intentional shot of Nam-ra and On-jo (Su-hyeok and Cheong-san's respective crush) looking up at the scene going on from the window one floor below.
As Joon-Young is logging into Facebook to find news about the zombie outbreak, Dae-su mentions he’s on Instagram. Joon-Young asks how many followers he has, then Dae-su dismisses it and tells him to just log into Facebook.
Even though what happens next is not pretty at all, as Na-yeon seemingly apologizes to Gyeong-su for insulting his financial status, everyone else is peeking through the recording booth’s window and gushing with excitement. They get even wilder as she starts wiping some blood off his hand.

Su-Hyeok brings up a detail often forgotten in zombie media: bathrooms. While everyone is thinking about how they can relieve themselves, Joon-Young is holding Ji-min’s thermos as if he were contemplating to pee in it before On-jo can give him a blank stare that essentially tells him "no".
- Once On-jo is able to get a temporary bathroom set up, everyone’s reactions of relief and disgust can be hilarious to watch.
Orangibberish is a hilarious Take That! at streamers who are willing to do the most stupidly dangerous acts for views. He never stops streaming so long as he has his camera, and even tells the audience to like and subscribe during life-threatening situations. The people in his stream chat are also hilarious to watch as they are equally concerned, snarky and condescending. The first-person view of his camera can also be more funny and entertaining to watch than it is scary.

Class 2-5 is trying to start a fire before nightfall and Nam-ra offers her lighter only after all of them had a turn of struggling to light one. The shocked look on their face is priceless as she could have saved all of them the trouble. The scene is meant to be a shocking revelation that Nam-ra is a smoker, but it ends up being more Played for Laughs.
- One small funny yet cute detail is Nam-ra only revealing the lighter when Su-hyeok is taking his turn trying to start the fire.

Cheong-san finds an expired candy bar in the gym storage room. While everyone was able to drink within four days, they have not eaten. To make sure everyone gets a fair share, they each take one small bite and pass it around. The whole while Dae-su is paying close attention to the bar getting smaller and smaller with each bite, with some students even passing on the chance to eat something. During his turn, he finishes what’s left and it turns out Joon-young has not eaten his share yet.

An In-Universe YouTuber had caused panic in a public train by staging a false zombie incident. He is later seen making an apology online and fakes out the audience by revealing he had no remorse and starts performing the “knee-copter” with a shit-eating grin and tone.
Jae-ik tries to comfort a little girl who just lost her mother by trying to hook her up with his son of a similar age. It turns out she already has a boyfriend.
Jae-ik prepares to leave Cheong-san Fried Chicken and asks Ho-Cheol if he’s ready, he tells him he’s not. Cue a Gilligan Cut where he’s screaming his lungs out on the back of a motorcycle and striking down nearby zombies with a stick.
- Ho-Cheol is screaming the entire motorcycle ride, much to the annoyance of Jae-ik.
When everyone gets ready to leave the rooftop in pairs, Dae-su offers his hand to one classmate after another and is rejected by everyone.
Dae-su shoots his shot and confesses to Wu-jin’s sister Ha-ri. He makes it clear that he’s been cheering for her in all of her competitions and admits he’s been calling Wu-jin his brother-in-law. He promptly gets kicked and beaten by his crush.