Awesome Aussie: Zigzagged. Australia may be feared as a badass or he might instead be mocked for the Emu War or rabbit plagues.
Abusive Parents: One comic shows that the reason he gave Papua independence is because he is lowering his HDI and he seems happy about it. It may be subtle but the boy was under his care and the HDI may be low because...
Berserk Button: He currently has a lot of problems with immigrants, and thus anybody trying to enter his country usually elicits either a huge rant that manifests in a Wall of Text or a simple "FUCK OFF, WE'RE FULL!" from him.
Break Out Character: Most people have not heard of Palau. However his young age relative to other countries (allowing him to be depicted as a baby) and the fact he has never been to war or really done anything bad has endeared him to authors.
The Cutie: Started out as one out of universe but has been portrayed as such in-universe◊ as well due to his childish attitude and the fact that he has never gone to war with anyone.