It's basically a dinosaur. https://en.wikipedia.org/wiki/Cassowary

From what I understand, all birds are basically dinosaurs.

Yes, but this one looks like one, in the sense of "show a picture to someone who doesn't know about them and they will not believe that this is a real animal alive today".

>Some New Guinea Highlands societies capture cassowary chicks and raise them as semi-tame poultry

emphasis on the semi!

for a simple overview, see also: https://www.rainforestrescue.org.au/save-the-cassowary/evolu...

It shares its name with the cassowary plum - a poisonous fruit that cassowary bird can happily eat, having adapted alongside it.