New Ghost?

Let me tell you about what I just saw. I just logged off of Minecraft, not because I was scared of seeing it, but I had to get the word out that SOMETHING was out there. No, I can assure you, this is not a creepypasta.

I started building this AMAZING wooden house with multiple stories below the ground on top of a mountain, lots of windows, etc. (I love my windows). When I was preparing "Floor Level -1" with all of it's windows (basically a whole wall of glass panes), I still had some more sand being smelted into glass. When I ran out, I ran back upstairs and right before I right clicked on the furnace, I heard a piece of glass break. I dunno if I was hearing things, because it's pretty late and I go crazy, or something actually happened. I forget about the glass and go downstairs to be Mr. Detective and search the scene. No glass broken. Nothing. What the hell?

I ignore it, go back to finishing up my house, and forgot about it ever happening. Now lately, I've been seeing things on Minecraft. I dunno if it's blindspots, lighting in the room, idk, but it's either completely different from any of the other times I've seen things, or fairly similar.

Sorry, I'm getting sort of off topic from what I saw. As I said, I just logged off, so my memory is still in-tact (considering I have A.D.D. and can't remember anything 10 minutes ago) and thought about this forum subject and thought "I gotta do this now, so I can get the word out there". Here's what I saw.

I have a 4 block tall lobby part of the house, which is above level, on the top of the mountain. I usually get spiders up there a lot, so anything up there doesn't surprise me. As I walked up the stairs, I see this faint spider looking thing jump off the top. "Oh okay" I think, but as I look back on the sighting, it was no spider. It was ALL black, with legs all the way around it, and a box in the center.

wat.

I check my minimap for mobs (entity radar) and there weren't any agressive mobs, just the chicken farm I had downstairs. I don't usually freak out about things I see really quickly. Only things I get a good sight of. This is the first time I've seen this. I'm probably going to go back to the world tomorrow and just start building again, but if I see or hear anything else, I'll update this thread. I'm going to call this spider thing... uhm...

Araknis

Yeah that sounds good, Araknis.

EDIT 1 (12:38pm June 14, 2013): I heard a sound like wood planks were being placed down. Might not sound that strange, but the fact that I don't have the game open is kinda weird. I'm not sure what to expect next...