Amazon Device randomly showing up on Network.

The answer has been posted here several times, thanks guys. Turn off WPS in your router settings and you won't see any of these devices ever again, I can assure you.

You'll continue to see them if you don't turn off WPS but they won't do you, or your system, any harm.

So I did some investigating and if you want it is easy to repeat the same steps. Go to your router management page and check the list of connected devices. I will bet you the mac address of Austin will not show up. As many people have been theorising Austin does not actually exist. It's some kind of software glitch - a device isn't actually connected to the network.

Sounds to me like you've got someone who hacked your Network's Password.  They shouldn't show up if they aren't a part of your network.

I would recommend changing your PW to something that is 16-32 characters in length, mixing capital and lowercase letters, numbers and special characters.  An example of personal favorite of mine is QWER!@#$qwer1234

Good luck!

Edit: Bad proofreader

I have the same issue on my win 10 16299.371 build.  The device ha sa MAC id 78:el:03:19:66:32, Amazon model KFDOWI, no other identifiers.  It shows up when I first access my network, disappears shortly after I check its properties.  I reset my network, pass codes and allowed devices.  Network has to prompt for permission for unknown devices.  This device doesn't show up in the IP lists in the router as an allowed or blocked device.  This started happening a few win 10 updates ago.  So many people have this issue, something is fishy.  This is not likely a network issue but is likely a software issue. 

Similar issues are happening on random passcode set networks.

I was also experiencing this, getting one called full_biscuit; usually pertaining to an amazon echo device. My PC is wired but I have other wireless devices on my personal network. The MAC did not match any of my devices. Additionally on router logs this device had never actually connected to my network or had been assigned an IP in my internal network.

I am sure security was good but went back and updated the wifi passwords on the network. The device still popped up eventually. Looking deeper into my router settings I saw that my router had WPS enabled; I thought I had this off but I guess not. When I disabled WPS I noticed the strange device went away. It has not returned yet after a day.

So TL;DR: turn off wps on your router. These are probably the neighbor's amazon devices scanning for connection points. for some reason when they hit your router and try to connect with it via WPS, your router might send that information to your PC's network locations view.