Complex sentence: He views Mr. Pickles as a monster and is only trying to protect himself and his family from the dogs evil nature, however he himself is unaware of Mr. Pickles protectiveness towards young Tommy.
Split into simpler sentences: He views Mr. Pickles as a monster and is only trying to protect himself and his family from the dog's evil nature. However, he himself is unaware of Mr. Pickles protectiveness towards young Tommy.