I am assuming you mean helpful or harmful to humans here, since the members of the animal kingdom are not inherently good or bad, they just are what they are.
Many animals are helpful to humans; many varieties of livestock (cows, sheep, pigs, goats, poultry) are kept because they add protein to our diets in the form of meat, milk products, and eggs. Fiber bearing animals such as sheep, llamas, and alpacas provide raw material for making clothing. Animals have been our beasts of burden for many centuries, carrying loads, pulling plows, and carrying humans. The dog has had a huge impact on the development of societies all over the world, because dogs can be bred and trained to hunt for us, herd other animals, pull sleds, guard us and our possessions, and be a companion in many ways.
On the harmful side, some members of the animal kingdom can harm us physically (grizzly bears, sharks) or can carry diseases that we can catch (mosquitoes, rats and mice). Some animals damage our houses by eating the parts that are made of wood (termites, wood ants, squirrels and porcupines), and others consume food that we were growing or storing for our own consumption.