Spookiest? None of them have been spooky, or particularly dangerous. The snakes tend to bolt when they see people. This one was just so focused on hunting/feeding it just didn't see me at first.
Actually, there was a point almost ten years ago when I felt a little uncomfortable.
I was in Far North Queensland and had stopped at some place called Dead Dog Creek (or something similar). I had been looking at birds, but the creek was all but dried up, and the creek bed was covered in dead leaves that had been washed there and just remained when the water dried up. There were a few pools left amongst the rocks, some quite deep, and I was hoping to see some turtles but I wasn't finding anything. Then I heard a splash from 20 metres away and I saw a shallow pool by the side of the creek. It was about 1 metre wide and 2 metres long, and was between the bank and the huge pile of dead leaves. It looked like this was the last place the creek was flowing and the leaves hadn't yet had a chance to collect here. AS I watched I saw the surface of the pool ripple, and as it looked to be only about 20cm deep I thought I should have no problem finding what ever it was. And I had my camera.
The only problem was, in order to get here I had to step off the rocks and walk through the dead leaves. My first step and my leg went down into the leaves, halfway up my thigh. My second step was the same. Each step was very slow and laboured.
Eventually I was a few short metres from the pool and I looked carefully at it to see if I could spot what it was that had caused the ripples. I didn't risk getting too close in case it was a lizard and I scared it away. At first I couldn't see anything but after a minute a small snake swam out from under the shelter of a small plant growing on the bank over the water. It quickly swam across the pool, popped up it's head, very briefly and then continued into the pile of dead leaves heading in my general direction.
I'm sure it wasn't aiming for me - it probably didn't even know I was there - but the fact it could move through the leaves with ease was a little disconcerting. Especially so because, when it had briefly popped it's head up, it was long enough for me to see the head was a creamy colour, contrasting with goldeny-brown body. A baby coastal taipan.
I shifted my weight around from one foot to another, moving my feet around, so the snake would avoid me and I guess I was successful. I waited to see if it would surface somewhere I could photograph it, but I never saw it again. After a few minutes I turned around and waded back through the leaves to the car.
Not really spooky, and although I'm sure I was safe from the snake I would have felt less exposed if I had been able to move more freely.