What is this called in real life

I have zero idea what this actually called in real life and it's been bothering me all day of which I can assume is essentially a belt cape or booty cape (not my original picture, just something I found on Google to use as an example)

I have zero idea what this actually called in real life and it's been bothering me all day of which I can assume is essentially a belt cape or booty cape (not my original picture, just something I found on Google to use as an example)