Shappish is another word for being quick to get annoyed and angry. The entity would spawn if you are in a multi-room key room and when you see the guiding light, you ignore it and run to another room, this thing appears for five seconds and if you haven't left the none key room, it ends your run with the jumpscare shown in the project. The jumpscare is made of random sounds from the internet distorted. The prototype sound in the sound tab is random Scratch library sounds combined and distorted.
Game over screen thing is a combination of code from @GamerRhys92-1 and @CompleteChaos77