Added to Furbish page: https://official-furby.fandom.com/wiki/Furbish_(Furby_Fake)

there is another with a black sensor cover.

I really like its posable arms!!

Furbish (Furby Fake)Official Furby Wiki

The sensor cover just looks black due to the light at the time when the photo was taken. There are many examples of regular Furbys sensor cover looking black:

https://i0.wp.com/boingboing.net/wp-content/uploads/2019/01/MzE5NjMzNA.jpeg

i0.wp.com

I also found https://jp.mercari.com/item/m37547878494 this listing for another Furbish by the same seller. When the description is translated to English it straight up says it’s a “Furbish and Furby combination.” They say the outer part is a Furbish (the fur) and the inner parts are from a Japanese Furby. Edit: While I was looking through the sellers page, I found a 3rd Furbish/Furby hybrid. https://jp.mercari.com/item/m93030766617 This one has no possible arms, and it has white eyelashes that are the same as a regular Furby.