The Angry Sun from Super Mario Bros. 3. It's locked on the screen horizontally and remains dormant until Mario reaches a certain screen (customizable with the first extra property byte), at which point it starts spinning in circles and swooping down in attempt to hurt Mario. It can be killed with a star or a thrown object.
If the Extra Property Byte 2's first bit (i.e. set it to 1) is set, it will instead use the Super Mario Maker 2 graphics set and animations.
Setting the Extra Bit will cause the sprite to look like the Happy Moon enemy from Super Mario Maker 2. Touching it will cause it to instantly kill all sprites that are not set to "Invincible to star/cape/fire/bouncing blk". Do note that while the SMB3 graphics are in effect, the Happy Moon will NOT display properly. You will need to remap the sprite if you wish to have the Happy Moon and SMB3 Angry Sun available in the same ExGFX file.
Note that this sprite disables L/R scrolling for any level it's put into in order to prevent an issue with following the screen.
7/12 update: removed debug code that was causing the enemy to die when pressing down
Works mostly fine, though there is an issue where the sun acts like the moon if you're flashing and hitting it on top of it. The reason for the weird behaviour happens because the default interaction only clears carry only at the beginning of the routine (e.g. when you kill it with a star or stomp on it) but not later in the routine like when you're sliding on the sprite or flashing. The moon also is a bit glitchy as Yoshi gets scared by it (though there is no easy solution except you add the flags yourself) and you also remove just the sprite which Yoshi has in the mouth but not whether Yoshi has something in the mouth or not (as a result, Yoshi spits out the sprite in the current sprite slot after taking the moon despite having "nothing" in his mouth).