Your design is a bit unorthodox, Animal::getAnimalobject() is inherited to Dog and Elephant unnecessarily. What you need to do is:

1. Move all the abstract functions in the interface,
2. Have your Dog and Animal classes implement the interface,
3. Continue creating them via a factory method, as you currently do.

...and you'll probably want to rename Animal to AnimalFactory.

Your design is a bit unorthodox, Animal::getAnimalobject() is inherited to Dog and Elephant unnecessarily. What you need to do is:

1. Move all the abstract functions in the interface,
2. Have your Dog and Elephant classes implement an Animal interface,
3. Continue creating them via a factory method, as you currently do.

...and you'll probably want to rename Animal (the class) to AnimalFactory.

Since you have an abstract class, I'm assuming you have a couple or more classes inheriting it. What you need to do is:

1. Move all the old abstract functions in the interface,
2. Keep the abstract class as a regular class with the one concrete function, and have it implement the interface.

You don't really need to change the classes that inherited from your abstract class.

Your design is a bit unorthodox, Animal::getAnimalobject() is inherited to Dog and Elephant unnecessarily. What you need to do is:

1. Move all the abstract functions in the interface,
2. Have your Dog and Animal classes implement the interface,
3. Continue creating them via a factory method, as you currently do.

...and you'll probably want to rename Animal to AnimalFactory.