The present study compared the effectiveness of virtual influencers (VIs) to human influencers through the theoretical lens of the uncanny valley and parasocial relationship using an online experiment. Specifically, we posited that highly humanlike VIs may evoke the feeling of the uncanny valley, as compared to human influencers or cartoonlike influencers, which, in turn, would act as a psychological barrier to building a parasocial relationship with the specific type of virtual influencer and decrease advertising attitude. The results indicated that people do feel the uncanniness from both highly humanlike and cartoonish influencers as compared to human influencers. This particular psychological experience negatively influenced the parasocial relationship, which, in turn, negatively affected the attitude toward a social media advertisement featuring the VIs. However, importantly, this effect was moderated by individual differences in anthropomorphism. This is one of the first studies that directly compared the effectiveness of different types of social media influencers in a rigorously designed experimental setting and expands the previous research on Vis, uncanny valley, and parasocial relationship. Both theoretical and managerial contributions of the study were discussed.