You certainly can
, but in doing so, you may inadvertently induce a major potion of the forum to consign you to a fiery pit forever and then deftly RMB -> Adblock your unsightly self-depiction.
Furthermore, before embarking on such a reputation-altering mistake, I suggest that you ponder the significance of such rules as these:
The Rules Thread wrote:
Avatars and Signatures:
Keep your avatar below 150x150. Failure to do so will result in it being stripped and you will lose avatar priviledges. Animated avatars are frowned upon.