The Heresiarch appears as a somewhat physically effeminate young man, with braided, spiky black hair and pale, scarred skin. His eyes match the current colour of the moon. His legs are insect-like, and his most prominent features are his double-tails, resembling that of a fattail scorpion, which constantly drip venom, and his spiderspitting cobra-like fangs, which poke out of his lips. He also has a halo resembling the rings of Saturn, made out of thousands of miniscule semi-transparent ice shards.