The angry sun is an enemy that made an appearence in 1 game, which is SMB3, and in only one level. While Newer SMBW brought it back, you can actually replicate the functionality. One problem is, though, is that it doesn't come down at you like the actual game, but it does "rumble".
1. Place either a podaboo or a spiny in your level.
2. Place a mushroom on the podaboo/spiny.
3. Place wings on the podaboo/spiny.
3. Put the podaboo/spiny in a cloud.
4. Enjoy the "Angry Sun"
If you make the cloud and wings invisible and replace the podaboo with an image of the angry sun, it could actually look like if there is a real angry sun.