User blog comment:SamwiseFilmore/How to Remove a Background Using GIMP/@comment-25533095-20160419120422

A better way to do this is just using the selection lasso tool. Slowly select what you wish to keep, click by click (it can get very detailed), and once you're done selecting, right click on the image, choose the "select" arrow menu, and press "invert".

Then you just press the delete key on your keyboard and you should get an image with a transparent background