Advances in realistic graphics and artificial intelligence are hallmarks of evolved video games, as environments and characters are made to seem more real. Little is known, however, about whether or not character model changes may impact players’ relationships with familiar avatars, especially since anthropomorphism—the perception of nonhuman objects as being human or humanlike—is understood as central to player–avatar interaction (PAX). This study leveraged a naturally occurring change to massively multiplayer online game avatars to conduct a field quasiexperiment to investigate whether enhanced avatar anthropomorphism influences PAX dimensions: emotional investment, anthropomorphic autonomy, suspension of disbelief, and sense of control. Longitudinal analysis showed that enhanced anthropomorphism had no significant impact on any PAX dimension immediately or over time, when controlling for demographic and gameplay variables. Player comments suggest the change was experienced not as a change in humanness, but as a shift in perceptual realism—believability, lifelikeness, depth—that impacted the experience of the avatar-mediated gameworld more broadly.