JSYK imgur just copies the link to the gallery. To get the image URL you need to right click on the image itself and copy its address. (Or... do something else if you're on an Apple. I have no idea how that shit works.)
Your best bet is to redraw the sprite in the size you want.
If you'd rather not redraw, you can also resize the sprite but preserve hard edges.Although, it'll only look good if it's a multiple of the original size (example, 200% bigger, 300% bigger, etc).
The middle one is probably closest to what you want, I'd imagine ^_^