A compsognathus measures 3 feet long from its head to the tip of its tail and weighs 15 pounds. It is small enough to serve as a house pet or even as a familiar for a spellcaster. In cases where magical links aren't involved, however, those encountering or keeping the creatures would be well-advised to treat them with the same caution one might extend to a pet viper or other poisonous reptile, as they are at best partly tame.