CARE to POOP.

Every letter change

1. CARE → CAME: change letter 3 from R to M.
2. CAME → CAMP: change letter 4 from E to P.
3. CAMP → COMP: change letter 2 from A to O.
4. COMP → COOP: change letter 3 from M to O.
5. COOP → POOP: change letter 1 from C to P.