1.Scientists brought back dire wolves after 12,500 years.
2.Three pups born: Romulus, Remus, and Khaleesi.
3.Used ancient DNA and gray wolf genes.
4.Romulus and Remus weigh over 36 kg at 6 months.
5.Dire wolves are bigger than gray wolves.
6.Pups live on a 2,000-acre secure site.
7.They are shy around humans.
9.Scientists plan to revive other extinct animals.