Cheese Dragons are not actually alive. They are enchanted items of food that act almost identically to dragons. They have no need to eat, but they must “live” in humid environments or they will dry out and harden.

Zex is not actually a living dragon. It is a moving Cheese Dragon that is used for food when the clan runs out of it. In the clan's language, "zex" means "cheese", which describes why they gave it that name. Even if a dragon takes one half of Zex's body, Zex will always grow a replacing piece back within seconds. It only likes to stay in mild tempuratured areas so that it won't melt or harden.