Convert it into a gif or jpg. That will make the Pink background go away.
First, never tell anyone to converst something into a jpg that has sprites, becides jpg's cannot handle transparent backgrounds and they flatten the images so the clolors blend togeather, thus ruining sprites.
Converting it to a gif wont work eather unless he manualy erases it
If you have fighter factory, here's a quick way to make it into something with a transparent background
Then when you put it back in, just add the image twice, hit active transparency and hit left or right between the 2 versions you added to FF, it will now show as transparent, then at the top you can use the save sprite as option to turn it into a gif or a whatever.
Just never, never use jpg