I mean, I see no point of Zombies breathing. I'm thinking that is the reason why zombies eat other ponies. They need some form of energy to move, don't they?

4085445
Technically a zombie can't even digest food, on account of his/her organism not functioning/being capable of working without the digestive tract

Conclusion is that a primal instinct just makes them feral and hunting for food. The book "Zombie Survival Guide" shines more light on the subject.

4085532
I see. I'll be sure to look at that some time. Thank you :)

Interesting question. The modern zombie is just about always a metaphor for humans as violent consumers; the role of zombies in films and how they function tells us a lot about that decade's self-identity. Zombies are canon, or at least, ponies tell stories about zombies. What's the part of their culture that they most fear? In a utopian society, what are they afraid of becoming?