animal.dart

abstract class Reptile {
  void bite() => print('Chomp');
  void swim() => print('Swimming');
  void crawl() => print('Crawling');
  void hunt() {
    print('${this.runtimeType} ');
    swim();
    crawl();
    bite();
  }
}

class Alligator extends Reptile {
    // Alligator Specific stuff...
}

class Crocodile extends Reptile {
    // Crocodile Specific stuff...
}

main() {
  Crocodile().hunt('Deer');
  Alligator().hunt('Fish');
}