Astaroth is rather tall looks to be quite muscular, although it is hard to tell with his bulky armour on. From before he was cursed to fuse to his armour, he had medium length black hair, fair skin, and purple eyes. He has four long curved black horns that point upwards, two on either side of his head. He sports standard purple demon wings, but they have some holes and tears in them, it is unclear if they were always this way or if he was wounded. His tail is black and looks like a snake, the tip glows a bright purple and when he gets angry or serious it gets coated in a purple flame. He's always seen in his full set of black armour, and wearing a white cloak.
- Few people but Astaroth himself knows what he looks like under his armour. Some speculate that, since the other Demon Lords are quite attractive, that he must be too. Astaroth has yet to give a definitive answer to these theories about him.
- Astaroth, along with Lucifuge are the only two heirs of one of the original seven Sets that do not have an "Original Form". This is because they are both replacing the original heirs of their sets.
- Astaroth was previously one with Kiran in the form of the Fallen Angel Azazel, who was split into two beings for defying the Gods. This means he is not even truly part of the Astaroth bloodline.