Shambling Along (Expert) is the first stage in Zombie Awakens!.
This is arguably one of the easiest Awakening Stages due to the underwhelming health of each Skelecat (only 25,000 HP), and large groups of them can be easily demolished with any Cat with a high Area Attack like Crazed Bahamut Cat.
When the battle starts, save your money. When Skelecat appears, begin spamming meatshields, then spawn Paris Cats whenever you can. After a couple Skelecats die, continue spamming meatshields and Paris Cats while leveling your Worker Cat to level max, to eventually spam everything you have.