My experience (100% true) took place in Melbourne, around 1993. I hadn't experienced anything remotely close to this before and haven't since. I was living in a house in Orrong Road with around 4 flatmates at the time. I had been living in the house for about a year, with no strange / unexplainable events.
One night, in the early hours of the morning, I was awoken (and believe me I was wide awake) with the realisation that "something" had entered my room. The interesting part was, although I couldn't see what it was, I sensed it was part human / part animal. I don't know how I knew this but I did. In other words, human but more animal-like. And obviously, the feeling I got from this thing was not pleasant. I was also completely paralyzed. Now I have read about sleep paralysis etc, but I was wide awake, and not the kind of person to imagine things. I was not using drugs or have had any history of mental illness / delusions etc.
Anyway, as I lay there I sensed this "thing" walk into my room, around the foot of my bed and stood next to my bed for a moment. I was reasonably terrified to say the least! Next thing I knew this entity was on top of me. I felt an extreme pressure crushing down on me, as if it was trying to actually get into my body. I didn't know what to do as I was totally paralyzed, so all I could think to do was to recite some kind of prayer to try and repel whatever it was. Now I'm not religious but I prayed for the first time in my life! After about 5 seconds it seemed to just evaporate away and I could move again.
It took me along time, but eventually I fell asleep. In the morning I got up to have a shower and I noticed on my chest 6 red marks on my chest, 3 on each side spaced equally apart about the size of large fingerprints. These eventually faded away over the course of the day.
The last and equally disturbing aspect of this experience was after I had showered, I went into the kitchen where my flatmate was getting his breakfast. I said "Morning" and he said turned and said in a mischievous way, straight off the bat, "Did the Bogey man visit you last night?" I instantly said "no" and nothing more was said. My flatmate was a bit strange and was into his runes and apparently "dark magic", but the fact that he somehow knew about what happened to me just put such a weird twist on an already very weird experience.
I wish now I had said "No, but why do you ask?" and got into a conversation. I guess at the time I didn't want him to think he had the power to summon things and send them off to freak out / attack people. I often think about that experience and have shared it in case other people have had similar experiences.