The whole series is about a group of mutated cats living together by themselves as strays in a small home that they created by themselves.
The group of cats started as the leader, Henry, who had lived with his family as a kitten. He was the only mutated cat who was part of his family, and so was not treated as much as most of his family did. Finally one day, a wolf named Lord Howl took away his family by getting his parents caught at the kennel. Henry's family was taken away from him, and even though he wasn't treated as well as the rest of his siblings, he was still very furious over the loss of his family. He ran off into the city of Carbondale and found a small opening near one of the stranded homes of the city. He created his home there, and as time flew by, more cats began to appear.
Two new cats came towards his home and asked to stay for a while. There names were MoonDusk and Sebastian. They asked to stay for a while. Pretty soon, they ended up staying there because they had no home. MoonDusk predicted that more cats were going to confront them.
Than came Captain Leonidas. Henry automatically accepted Leon into the group, because he liked that Leon had a prior experience to Military participtation. He than had seen Lar, who was asking to join them for unknown reasons that Henry knew of. He let him join them as well; Pretty soon they named themselves the Proud and the Mutated, due to the mutations of themselves that no one wanted to take care of them. Henry noticed that Lar was the only one to be able to speak to the humans. Pretty soon, Tigeo came along. They begin doing adventures and roaming the streets finding food. They began walking into alleys and met Skaye, a spoiled and rich cat who wasn't used to strangers. She was tired of "living like a dog," and so asked to join them on their adventures. Soon she thought that their group name, The Proud and the Mutated, was far too ugly for a name. She requested that they would rename the group EpicCats. The others agreed, and so their name was changed soon after.
Finally, they found a crazy stray named Angie appear to them. She kept staring and entering their home taking food. When Henry caught her doing so, he was automatically going to kill her because of her threat towards their supply. Angie, being the mentally insane cat that she was, said a bunch of crazy explanations that confused Henry. Eventually, the other cats believed she would put good use to taking supply from other locations, and so asked her to join them. Henry hesitated, but soon agreed. Angie than became part of the EpicCats.
Now Henry and his group continue to do adventures and make life worthwhile. Henry still tries to hunt for Lord Howl, while Lar still looks for Vlar, his enemy.