What we all know happens when attempting to use lazily-made masks:
Here I'm going to explain in detail about fixing these lazily-made masks:
After opening broken image, I recommend set zoom to large size:
Take "Magic spell" tool, and set selection mode to "Append":
And click to all background areas on image for check them to "selected":
Take brush tool, and set any large size:
Don't forget to set foreground color to White:
And we can paint over background, for fix wrong color of background:
Now, you must invert selection and change foreground to black:
Paint over non-transparent zone by black color:
And image was fixed
Now, you must save image:
Don't forget set both values to 0:
And mask was fixed!
Sprite-designers, please don't make lazily-made masks next time!
And save files as the real .GIF, not .BMP renamed with the .GIF extension