Be careful.exe and turn back.exe
There are two M.U.G.E.N mods that were made to be creepy, called "be_careful.exe" and "turn_back.exe." I will be talking about both in this same article, as both mods are very similar.
be_careful.exe
be_careful.exe has a WinMUGEN title screen without text. It's only character is ".EXE" which is a Sonic.exe edit that performs these actions exactly: 1. It opens it's eyes, and then closes them again. 2. It floats up, and then teleports away. 3. The original Sonic.exe jumpscare pops up, and 10 frames after, the game crashes. It is unknown who created this project. The only information I can get is the name of the screenpack's creator, which appears to be "666" but that's all I can find.
turn_back.exe
turn_back.exe's title screen has no text or background. It's only character is "William...?" which is essentially William The Hedgefox without a tail and with blank eyes. It performs the same exact actions as ".EXE" but instead it shows a spooky Ronald McDonald image. The project's creator seems to be the same as be_careful.exe's creator.
Story
I was walking down the street on a cloudy day, and I saw an old man selling some CDs at a yard sale. I saw what he was selling, and it turns out he was selling some M.U.G.E.N projects. I asked how much for them, and the man said, "Why, you can have one of these for free! I don't mind." Then I asked, "By any chance, can I get your name?" And the old man responded with "Gary." So, being excited, I picked up a CD and sprinted home. When I got home, I put the CD into my computer. I turned it on and started Windows. There were two projects on the computer. Both were labelled something strange. The first one was called "be_careful.exe" and the second one was called "turn_back.exe". I opened the first one, and it appeared to be blank. I selected the only blank option, and I selected the only character, which was called ".EXE". It showed a Sonic.exe for a few seconds and then there was a jumpscare. I almost pissed my fucking pants. The game crashed about 10 frames afterward. I thought to myself, ''What a fucking experience. I might as well try the next one...'' And so I did. It seemed to be the same, but everything was missing. I proceeded to the next screen, and I selected the character. It was called "William...?". It showed what looked like a Gary Stu. It was a green Sonic. I didn't like Sonic Gary Stu's. Same actions as the previous project, but instead of a Sonic.exe jumpscare, it was a photoshopped image of Ronald McDonald. Again, I almost pissed my pants to see there was something different. I took out the CD and smashed it. I looked back at my desk to see that there was another copy waiting right there for me. I smashed that one, looking at my desk. I turned to see that it was on my bed this time. I kept on smashing it until I had come to the conclusion that I should return it to the original owner. I went back to the dilapidated house I found the thing at. The old man wasn't there now. I asked a person walking on the sidewalk about Gary, and they responded with "Oh, you talking about old Gary who used to live here? He died while playing M.U.G.E.N outside during a thunderstorm." I just stood there in shock as they walked past. I then threw the CD at the house, snapping off a piece of wood on the side. I shouted, "Take your haunted M.U.G.E.N projects back!" A few moments later, another M.U.G.E.N fan walked by and picked it up.