Answer:
I am needed for most animals and hardcover books
I can swim but never get wet. I can run but never get tired. I follow you everywhere but never say a word. What am I?
I never was but always will be. No one ever saw me but everyone knows I exist. I give people the motivation to better themselves everyday
I go around a yard but does not move.
Though not a plant I have leaves. though not a beast I have spine. Though many wouldn't need me I am more valuable than wine.
Those with eyes bigger than their stomach will definitely leave the restaurant with one of them. It is named after a house pet as well.