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.

Swiss Mirth, like a lot of cheese dragons, is highly paranoid. He (for that's the gender that he calls himself) normally hides himself in his den and never comes out. Since he isn't a live dragon, he has no need for food or water. Swiss Mirth used to not be so scared of other creatures. He was once a very cheerful and happy dragon, which gave him the second part of his name, "mirth". Then one day, when he was wandering about in a nearby forest, he felt the tip of his tail go numb, almost as if it wasn't there. When Swiss Mirth looked at it, the tip of the tail had been munched off by something in the forest! Swiss Mirth immediately went to hide in his den, even though after a few weeks and some mysterious thefts of Swiss cheese in the area, his tail was regrown. Now Swiss Mirth never wanders about again and the other dragons hopelessly try to convince him that, no, nobody is going to eat him if he comes out.