Which animal produces a hard shelled egg that matures outside the mother?

Answer;

-Bird.

Explanation;

-Birds reproduce by internal fertilization, during which the egg is fertilized inside the female. Birds have cloaca, or a single exit and entrance for sperm, eggs, and waste. The sperm from the male is transferred to the female when they touch cloaca, an act referred to as the cloacal kiss.

-Birds' eggs get fertilized inside the female bird's body, before the shell is formed. Then each egg comes out before any development of the fertilized egg starts.