This moon will either flee for you, or attack you. The latter can't be killed in any way, and it can't be collected. The fleeing version can be collected, but it's tough to do so. Once it's collected, it won't reappear again for that level, along with all other 3UP moon (sprite)s. You can disable this, as well as affect many other things in the define list. Credit not needed.
This can be a big surprise since it looks like a normal moon except when you think it was too easy, BOOM, it flees or attacks you.
Anyway, the changes I have made besides conversation to PIXI are to use Asar defines for the sprite customisability (though the extra (property) bytes could have been used instead but w/e) but also made the palette editable on the CFG file and added suboffscreen so that the sprites still don't run when they're offscreen.
The sprite also didn't come with an ExGFX which I have included now.
I also tried to unsuccessfully add a wall and ceiling dedection so the sprite looks weird at wall or doesn't pass ceiling so be aware of that when you put ceilings there.