"The zombies ate my brains."
Subject: Zombies. Which Zombies? The zombies.
They are doing the action.
Predicate: ate my brains.
The action is "ate."
The object is "brains." Which brains? My brains.
Why are my brains the zombies' object?
Do the zombies object to my brains so very much?
Perhaps because they have no brains of their own.
"Because they have no brains of their own" is a sentence fragment.
It has no action.
The zombies are fragmented.
Their only action is to eat that which they don't have.
The zombies ate my brains.
Then grammar ate the zombies.
Then the wolf ate grammar.