Clockwork’s body uses steam and a fan to float, which is powered by the clock in his chest. Floating is the only mechanic of his body that requires steam.
Clockwork’s body has 3 forms. The first is its default form, which looks like a copper version of his normal body with the steampunk gadgets mostly confined to his face for the sake of facial expressions.
The second form is called the vent form, in which panels on his arms and torso slide open to allow excess steam and heat to vent out. This is triggered by his body becoming too full of steam and keeps the copper from melting. Movement is slower from crowding of the joints.
The third is called the compact form. Triggered by a circular twisting switch on his neck, his body folds up as many internal and external components as possible to reduce empty space and allow Clockwork to fit into smaller spaces. After going back to his default form, Clockwork will automatically switch to vent form.
Danny, instead of having a steampunk ghost body, can turn into a spirit capable of possessing empty steampunk bodies. Same with Vlad and Dani.
Ghosts build their own bodies.
In the Ghost Zone, isolated piles of steampunk building materials that are half built up can be found here and there. These are a sign of a ghost building itself a body.
Ember’s ponytail is a giant stylized network of steam release valves and tubes. She probably thinks it looks cool with how the steam vents out.
Ember still dresses like a 90′s rock star.
Skulker’s hair is just steam that comes from a release vent that runs down his neck.
Primordials like Clockwork don’t build their own bodies. Either someone constructed a body they liked, or they found a body they liked and decided to inhabit it.
Though the observants built Clockwork’s body, they do not treat him like their slave. They treat him like a coworker or employee they’re wary of. However, they do keep a special key on them that winds all the weights of his chest clock at once while only allowing him to have a normal winding key as a method to keep him from trying to rebel.
Once a ghost possesses a body they like and decide to keep it, they’re stuck in that body until it’s destroyed. Only half ghosts are exempt from this.
Due to their bodies being made of physical objects instead of ectoplasm, ghosts are not able to turn intangible. However, they can turn the things around them intangible to bypass this restriction. They retain all other powers.
