I believe that Doomguy, the protagonist of seminal FPS series Doom, may have a more whimsical reputation than he deserves. The culprit? His belly, which is readily visible in Don Punchatz's cover art for the 1993 classic. Doomguy did not go into battle wearing a jaunty little cutoff tee, nor did he have a uniform purpose-stitched to display his impeccable abs, but I believe he may have left this impression on untold thousands (millions?) of gamers.
Whatever the in-universe explanation for the tummy window on Doomguy's outfit, it has become a persistent feature of his design in both fan and official works. When his OG outfit is replicated in the HD era, you always see the abs: Doomguy's classic skin in Quake Live has it, as does the equivalent skin in Doom Eternal
