They called mangoesteens queen of all fruits. I'm told that durian is a heaty (makes your body get heated up fast and the chances of falling sick is high) fruit, and eating mangoesteen cools your body down.
You can find mangoesteens in every durian season.
I used to eat them, but now I don't really fancy them. Probably because sometimes there is this yellow colour thingy attached to the flesh which makes some of them look bad.