The following incident went down in April 2012. I was in my second year of university and cramming like crazy for one of the scariest and most difficult exams of the semester.
It must've been 2 pm and I was studying in our department's library in the main building of my college. Our department takes up a corridor on the third floor and consists of some classrooms, cabinets, a library and the restrooms. It is usually pretty desolate with only few people hanging around, usually just waiting for a class to start or perhaps studying.
Anyway at that point I decided I'd had enough for the day and was going to go home. However, I needed to use the ladies' room first. I remember passing three or four people who were sitting at a table in the corridor and were studying quietly. There were three stalls in there, I went in the first one but the doors to the other two were also wide open. I was alone, enjoying the quiet, doing my business, didn't expect this little bathroom visit to be different from any other.
Then I heard it. First I thought it was just the sound of water flowing in the pipes or something and ignored it but as ten, twenty, thirty seconds passed the sound got louder and more distinct. It was laughter, a sort of continuous cackling in a very deep voice. I wanted to think it sounded almost like a villain's ominous laugh from a cartoon and thought someone was just screwing with me, but then the sound suddenly mutated and the only way I can describe it is that the laughter was joined by sounds of dogs howling and pigs grunting. It sounded surreal, not of this world and it echoed off the walls which made it ten times worse to listen to. It was going on for about a minute now, becoming louder and enveloping me more and more and I was just sitting there with my pants down, my terror growing with every second I stayed there. I had a really bad feeling, like something awful was going to happen if I don't get out of there. So I jumped up, yanked up my pants (more or less), I don't remember if I wiped, I don't remember if I flushed, I just bolted straight for the door like my life depended on it.
So there I was standing in the quiet corridor, quite disheveled, my eyes the size of saucers, mildly shaking and very confused. What did I just hear? After a minute or so I composed myself enough to zip my fly, close my jacket and I even managed to gather enough courage to open the door and take a peek inside. There was no one in there and it was dead silent again. No one's phone was ringing in there, no water flowing, no janitor vacuuming, no one laughing in the adjacent men's room (actually no one coming in or out of there in the next ten minutes I spent in the corridor going 'holy cow' over and over). I've thought about it quite a lot ever since but I'm running out of ideas what it could've been.
I actually decided against going home because my roommates weren't due home for hours. I was really too scared to go home and be alone at the time so I just went to a café and chain-smoked to calm myself down. Some classmates of mine came by, I told them about my little incident in the restrooms but they all either shook their heads in disbelief or laughed hysterically. Actually, no one I know seemed to experience anything similar there. And take into account I'd been using that restroom on a weekly basis for the good part of two years by the time this happened, I did not confuse this sound with any familiar sound that one would usually hear in there. One of my roommates, a Psychology student, said I was probably projecting because of the exam-induced stress and was just imagining things but I wasn't feeling especially stressed that day and besides, I know what I heard, it was with my ears, not my brain.
I can finish this story by saying it took me over a week to feel safe sitting on a toilet again and I've never heard the laughter after that one time.
I'm wondering if anyone ever heard anything similar or if you have any ideas what it might've been. Are there any entities known to sound like husky men/pigs/dogs?