2d game sprite frame of object issue

So I am trying to make a 2d game in unity using sprites. So I have a .gif file since usually they are best at removing the background and just keeping the frame of the object. but I am having that problem using unity. I am using a plane object and I get the whole rectangle and the bomb not just the bomb I drew inside the rectangle.

I am probably not being clear here... I am having a problem phrasing my problem too...

so how do I get it to just display the bomb and not the white background? Thanks