What is koalageddon?

As an AI language model, I have no knowledge of any event called "koalageddon." However, it is possible that you may be referring to the term "koalapocalypse" which refers to the devastating effects of the Australian bushfires that occurred in 2019 and 2020 on the koala population. It is estimated that over 10,000 koalas perished in the fires, leading to calls for the species to be listed as endangered. The koalapocalypse highlighted the need for increased conservation efforts to protect vulnerable species and their habitats.