Let's say a rich girl (let's call her Sera) adopted a baby tiger years ago. The tiger is an adult male, but docile with his owner. Tomorrow a zombie apocalypse starts and spreads fast across united states.
Sera knows that her pet is a good ally, but is not immortal, even if the virus doesn't infect animals. She crafts or buys a fine leather armor with metal plates similar to the ones that samurais used.
The house is not safe. She needs to escape from the city. She grabs some clothes, weapons, first aid kits and supplies for her and the tiger. Don't worry about that detail, they have enough for 7 months and the big cat can eat zombies or other animals, humans or even wildlife.
Sera has a modified hummer big enough for her and the pet tiger.
How hard is survival for sera and her friend? Is the tiger a decent guardian for her?
Notes: Zombies are mixed: some are fast, others are slow. They are not smart, but not so stupid. Balanced stats for the undead.
The destination of Sera is any remote location free from zombies, like a natural reserve or an island.