The anthropomorphic bias describes the finding that the perceived naturalness of a biological motion decreases as the human-likeness of a computer-animated agent increases. To investigate the anthropomorphic bias in autistic children, human or cartoon characters were presented with biological and artificial motions side by side on a touchscreen. Children were required to touch one that would grow while the other would disappear, implicitly rewarding their choice. Only typically developing controls depicted the expected preference for biological motion when rendered with human, but not cartoon, characters. Despite performing the task to report a preference, children with autism depicted neither normal nor reversed anthropomorphic bias, suggesting that they are not sensitive to the congruence of form and motion information when observing computer-animated agents' actions.