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.

A friendly, sweet dragon, this poor creature is nonetheless an outcast from his fellow cheese dragons... for he loves to eat cheese. More specifically, cheese that's been melted over crackers and nachos and select pieces of meat and, well, just about everything else

However, most cheeses regard non-intelligent cheese as sort of a 'crippled sub-species' and thus hiss and snarl at Munchymelt for his heinous actions. Luckily for him, however, dragons like the little 'We Do Fondue' and the aggressive 'Ham 'n' Cheese' also consider stupid cheeses to be, well, just cheese, and they are good friends with the outcast.