It seems the article's author won the 2017 Ig Nobel Prize in Physics for 'using fluid dynamics to probe the question "Can a Cat Be Both a Solid and a Liquid?"' The prize announcement[0] cites the current article.
Also relevant, down-thread, plink mentions the Bonsai Kitten[1] hoax from nearly 18 years ago now.
I'm pretty sure Bonsai kitten was a thing long before 2000. I remember seeing it as early as 1996, perhaps even 1995. It may not have had a domain name at that time, but it was certainly doing the rounds in the mid 90's.