THE YANDERE SIMULATOR TERMINATORS are people in Yandere Simulator who outrun and "surprise mother-f*cker" on Jay, who is playing as Yandere-chan. Currently, this group consists of the Teachers and the Delinquents.
The teachers have been Jay's terminator-enemies ever since he started playing Yandere Simulator. The Yandere Simulator Myths series has a lot of episodes regarding the teachers being terminators. They are the ones commonly chasing Jay and jumpscaring him. They, however, can be killed using Easter Eggs, or the Demon "Jazz" Hands, or if you have enough physical education, just plain homicide.
The Delinquents possess a lot of qualities, which can make them impossible to be escaped from. They are really dangerous, and Jay usually gets surprised and scared from them, since they get to where Yandere-chan is fast.
~Strong: They can hit Yandere-chan with their weapon so hard that they can make Yandere-chan have a severe comatose, they can push even the strongest Yan-chan, and they are not affected by the Falcon/One Punch Easter Eggs. Once they push a Falcon Yandere-chan, Jay cannot be able to press "CTRL" to make her Punch. After trying to punch again, Jay confirms that they must be really strong. [YANDERE SIMULATOR EPISODE: MEET THE DELINQUENTS!]
~Fast, Unli-Energetic, and Motion-Law-Breaking: When chasing Yandere-chan, Jay panics about them the most because they can run through walls, and when Yandere-chan teleports to the class, they don't run in circles like the teacher, they run through many walls and through the classroom, giving Yandere-chan a coma right away. They won't stop running until they will be able to make Yandere-chan feel what she did to the poor student she just killed.
~Invincible: They don't die from any weapon, they don't die from Easter Eggs, and they don't die from the Demon Hands. Jay confirms that they really are CURRENTLY INVINCIBLE for now. [YANDERE SIMULATOR EPISODE: DELINQUENTS AND TEACHERS CHASING ME! (Part of the Myths Series)]
~Flexible: Their head can spin 360 degrees whenever they want to, just like an owl. Jay knew this in the Yandere Simulator Episode "THE SECRET IDENTITY OF THE BURNING GIRL AND WEIRD DELINQUENTS"
~Aware: Even with their head turned back, they will still hit you if you try to attack them. No literal back-stabbing for the delinquents.