Hello how may I help you? I need to buy a birthday present. Who are you shopping for today? My son. His birthday is in 3 weeks. He will be 9 years old. What does your son enjoy? He enjoys creating things out of Legos and other types of building objects. He also loves animals. Would you like to get more Legos for his birthday? I think he might really enjoy that. However I would think something challenging would be best. How about a large Lego set? I think that would be perfect. Could you find a set that has a large number of pieces requiring many steps to create the final item? Yes, let me find you a challenging set.