Idols typically engage their followers through emotional expressions and interactions. Unlike real human idols, virtual idols are computer-generated avatars that do not exist in the real world. The impact of anthropomorphizing virtual idols’ emotions and interactive behaviors on follower reactions is still under investigation. This study analyzes 26,093 videos from 166 virtual idols on the Bilibili platform. The results show an inverted U-shaped relationship between anthropomorphism (both emotion and behavior) and follower recognition and engagement, providing empirical support for the Uncanny Valley hypothesis. Moderation analysis shows that behavioral anthropomorphism flattens the inverted U-shaped relationship between emotional anthropomorphism and follower recognition. Additionally, the moderation effect of the video category reveals that the inverted U-shaped relationship is steeper in entertainment videos compared to daily life videos. This study highlights the importance of balancing emotional and behavioral anthropomorphism when designing virtual idols to optimize follower recognition and engagement.