https://www.cnet.com/news/julian-assange-embassy-cat-has-the-internet-demanding-answers-meow/

The cat appears to have been just a kitten when Assange took it in, based on Instagram and Twitter photos. Its accounts began in May 2016. No new Instagram photos have been posted since March 2017, although the Twitter account was still retweeting in March 2018. 

During its time in the embassy, the cat played with celebrity visitors, including filmmaker Michael Moore, and did regular cat things, like hiding in a hat or slopping milk on the floor.