Lol. It is a normal sized avatar. I can't help it if his OS is from the cybernetic stone age!
No Kirinke, it is a wallpaper-sized (1,000px x 816px) image scaled down for most people browsing this forum (150px x 122px for myself). It even says wallpaper in the filename: wile_e__coyote_and_road_runner_by_fabulousespg-wallpaper.jpg
To save you the trouble, I've attached a scaled down version of your original image for you to use as you avatar, if you are so inclined.