Pancho the Cat

This is a tale about a battle for survival between the feline families that roamed and scavenged on the docklands of Liverpool soon after World War II and the vicious rodent hordes.
Food is scarce, fights to the death are frequent, and the rodents fighting in large numbers are murderous in their attempts to kill as many kittens as possible to keep the cat families small in number. The leader of the rat pack, Retsina, an extremely clever and meticulous rat, is a freak of nature because of his size. He is a giant among the rodents.
There is one large cat family who are a match for rats. They are the fighting Flynns who are led by Feral Flynn, a giant ginger tom, fearless and brave. He looks after his clan well. Battles up to now are even.
Then one night, a new cat hero emerges, a loner who is soon to become the hero among the felines, a scourge on the rodents, who is sharp as a pin, ridiculously cute, and braver and swifter than any feline. He has arrived.
Who is this stranger Pancho the Cat? Where did he come from?