these characters are all part of the same universe. Here's the story:
Oak was a kind and young mailman who worked twice as hard as the rest and was still paid little. Though he had very little money, he found himself comfortable in an old cheap cottage he rented. He made himself comfortable by watching birds from inside. His company got sued because one of their employees robbed someone's mailbox on camera. The company had lost a ton of money and barely had enough to pay their workers, so they chose Oak to get rid of. Oak couldn't find a job so he couldn't pay his bills. He decided to work for the military because he thought it was his only choice. One day a huge war went on, and Oak had to fight in it. Suddenly, he noticed a giant nuke coming towards him. He shouted and ran for cover just before it hit. After a brief moment, he turned around to see a bunch of people coughing around him. He noticed a strange green gas filling the air. Immediately he searched his backpack and put on a gas mask. He was lucky he didn't breathe in. He ran away from the fight. Soon there was a giant outbreak. The gas was turning people into zombies! The news spread quickly and so did the virus. In just a few days, the virus had spread across the world. Very few survived. Most of those who survived were either too old or too weak to travel. Oak hid inside his house, watching the world crumble around him. He broke apart his old bookshelf and blocked the windows using its wood. He locked the door and moved the couch in front of it. He opened the pantry and grabbed multiple cans of beans. He was going to have to survive there. He took a nap. He woke up to a loud banging sound coming from outside. When he looked, he saw that a ton of zombies had discovered his base! He quickly jumped out of bed. The zombie broke the window and started crawling inside the house. Oak ran back and started searching for a weapon of some sort. He was cornered. The zombies had surrounded him. He was toast (with butter.) Suddenly, something hit the ground. GRENADE! Oak braced for impact as he felt the waves of explosion hit him. When the smoke cleared up, the zombies were oofed. Behind the zombies was Twitch, an old friend of Oak's. She had thrown the grenade to save him. They jumped out of the window and ran towards her car. They drove away as fast as they could. On their way they see a teenage girl (Kate) hiding under a tree sharpening a stick. They call out to her. Kate aims the stick at them thinking they're zombies and calms down when she sees they're normal. They as a group get in the car and drive away. Because the story is getting too long I'ma make it shorter long story short they meet two-face, a cat who is partially infected but for some reason transforms a lot slower than others. He knows the location of a secret laboratory that creates the cure. Arrow, the cat who caused the whole outbreak, is the owner of it. Can they all make it to the laboratory in time? idk find out yourself