Strange image, it is partially transparent (A=199...). It looks like it was extracted from a black background, as a first shot:
1) add a black layer under, and merge
2) wand-select the black with a low treshoid
3) Select>Grow by 2 px
4) Colors>Color to alpha and remove the black
5) Erase the (artificial) waddle
However, close inspection of the resulting edge makes me thing that this isn't the first cut out the picture has been cut out before being transferred to the black background. (Edit: the "haircomb" histogram also hints that this image has been a GIF in a former life.)
Another solution is to use the path tool to make a cutout path slightly inside (1/2px) the current image. Not very difficult given the smooth lines of the contour.
1) add a black layer under, and merge
2) wand-select the black with a low treshoid
3) Select>Grow by 2 px
4) Colors>Color to alpha and remove the black
5) Erase the (artificial) waddle
However, close inspection of the resulting edge makes me thing that this isn't the first cut out the picture has been cut out before being transferred to the black background. (Edit: the "haircomb" histogram also hints that this image has been a GIF in a former life.)
Another solution is to use the path tool to make a cutout path slightly inside (1/2px) the current image. Not very difficult given the smooth lines of the contour.