A feral being is one that has escaped from domestication and returned, partly or wholly, to its wild state. Frisket is a feral dog, and is capable of leaving at anytime to go where he pleases. He is not dependent on Enzo Matrix for his survival.
Scuzzy could also be considered feral as he is fully capable of taking care of himself without outside help. He is also very intelligent, capable of communication and outsmarting computer systems.