The Cat Lady: What the hell did you bring into my house?
Jezelle Gay Hartman: Every 23rd Spring, for 23 days, it gets to... eat.
Darry: Eat?
Jezelle Gay Hartman: You know what it eats and don't you make me tell you.
Trish: The first time I heard that story, I used to think this would be the road I'd die on.
Answer: Since the Creeper needs various body parts i.e. eyes to see, lungs to breathe, it would also need to eat the hearts of its victims for its own heart to keep beating. Or she could mean that the Creeper is essentially devoid of all emotions as it keeps attacking anybody that has the body parts that it needs to extend its own life.