This series has controversy due to the questionable thumbnails.

There are female versions of the mobs, a Zombie girl is a good example.

Herobrine's pants get accidentally ripped off and his underwear is exposed.

Chucky urinates on Zombie, same happens with Pennywise doing the same to a Baby Zombie.

Moments where female characters are doing questionable stuff.

Herobrine kisses a female version of himself at the end of a episode.

A girl is tied and they throw some brown stuff to her, cringe and severe.

Despite being a animation, sometimes it is for kids, maybe it would receive a rating like TV-14 to TV-MA (Some episodes).

There is a series of episodes called "Boys and Girls", sometimes there's moments that people consider sexist.

Skeleton and Wither Skeleton jumps and in the air they are punched and they are hit against the fourth wall.

Some episodes contain gore.

In one episode Herobrine is run over by a car.

A character is sent at a funeral of Coffin dance meme, played for laughs.

Granny has her bat tainted by blood.

There is a episode set on Squid Game universe. (For some people that dosen't know Squid Game has very dangerous games)

Animated slapstick moments.

In "CHAINSAW MAN CHALLENGE", a character has many saws.

Zombie ties Saw, Pennywise and Granny and makes them near to spikes in the floor.

A ship is destroyed in one episode.

Despite the series that the characters are muted, there is a KRIK KRIK version that the character talk by subtitules, sometimes there is a track that says "WHAT THE F***".

In one episode, Herobrine dies being run by a car, then all the students get depressed. Herobrine revives as a zombie thanks to a radiation and attacks students, this would be upsetting and scary for some children.

Sad and emotional scenes: TV-PG.

Dark moments: TV-MA.

People don't gonna like the content written in "Sex & Nudity".

Inappropiate thumbnails.

There is a russian animation that is not related by Monster School, is about that a spider and mobs trying to stop a bunch of miners, there are sad moments, like Spider finding her wife dead and Zombie depressed by Baby Zombie death and furious, that animation done people feel sad.

A Girl takes out a mucus and throws it at Herobrine and the students, gross man......

At the end of one episode, a goat dies and Herobrine gets sad as we see a flashback of Herobrine and his goat friendship, then we see the students having a party in the school, this may offend and sadden animal lovers, but i think this is by comedic purposes.

Also there is many people ruining the series, with cringy thumbnails and stuff like that.

Very scary episodes like "AREA 51 RAID ALIEN APOCALYPSE" and "SCP CHALLENGE".

"Light In The Dark" is emotional.

In "Slap Kings" Creeper has no hands and can't win, this is played for laughs.

Mild/Moderate in most episodes.

People would be offended that in one part of the episode "Brewing", Enderman drinks a potion and turns into a mexican.

"DR NOOB CRAZY DOCTOR" is mildy scary, features a doctor that tortures patients.

There is another episode that i found called "Bad Monster vs Good Monster", is sad but at least has a message about sometimes altruism will make bad people become good people.

All the school looks like a dysfunctional family.

Like i said in "Sex & Nudity", there is a series of episodes titled "Boys and Girls" as i said that some parts are considered sexist, well "AMONG US WHO IS THE IMPOSTOR" is a example of such sexist moments like, Herobrine kicking Slime girl, Skeleton girl and Zombie Pigwoman being killed, etc.

Wither Skeleton wakes Herobrine with a hammer, then Herobrine goes to cry to the corner, played as comedic.

HAPPY NEW YEAR 2020 BUT HORROR may be scary for younger children.

Sadako is a evil spirit of a woman that in some episode frightens many much, however in actual seasons she is nice and not scary. (By a weird reason)