Same art style as this

^Not just that. The linked page has the URL of an image instead of a pixiv account as the website link, and going there shows you the exact same account as the artist.

They probably changed their pen name at some point. Their current Pixiv name is "Heytwo黑兎", and 黑兎 means "black rabbit". By the way, that's the same name, twice: in Chinese (the artist is Chinese) 黑兎 is read "Hēi tù" (or so Google Translate tells me).

Edit: Here's an older work signed as Black Rabbit.

last edited at Mar 1, 2021 3:32PM

Also, judging from the comments on the most recent art artist is deceased.

I didn't want to believe that, but their last blog entry seems to confirm it:

黑兔太太已于昨晚去世

which Google translates as "Mrs. Black Rabbit passed away last night."

And the penultimate entry (a mere 12 hours earlier) reads a lot like a suicide note. I'm not going to quote that one.