delved into the world of animation since the 1973-1974 The Animated Series. PXO took the franchise in a new direction when Discovery Season 4 adopted virtual production for the first time in the franchise's history. Strange New Worlds is the first new series to use virtual production from its inception. Game of Thrones PXO was brought on to the HBO television series Game of Thrones in Season 2 and remained through the final season. PXO VFX Supervisor Sven Martin and his team worked closely with the show's VFX group. Martin told Forbes Magazine that they wanted to depict the dragons as "living animals with just enough expressions to understand their feelings…similar to the emotional connection with pets." "We started with a base model, which was established in season 1, but we went for a darker, grittier approach," Martin told Entertainment Weekly. "We did a lot of redesign, made them more spiky, even in the baby state. It was a little bit of a relaunch, but we still kept it believable for the audience." The key to grounding these mythical creatures, which do not exist in real life, was to give Drogon, Rhaegal, and Viserion real-world animal counterparts the audience could identify with. "The dragons were always in close contact with the actors," says Martin. "And we were shooting outside on real locations. So everything is real and not meant to be a fantasy. We wanted to transfer that." Studying bird and bat anatomies influenced the dragons' wingspan design. The PXO team even dissected a supermarket chicken to get a sense of how the wings could move. Observing geese on the ground playing with their own wings was later emulated when the dragons were shown sitting down at ease. Color patterns were gleaned from frogs and cheetahs, while crocodiles, lizards, and other reptiles were used for skin structure. Martin's team met with the show's VFX Supervisor Joe Bauer at the start of each season to discuss new design elements, as the dragons were maturing and growing. For example, they became more guard dog-like as they grew into their roles as Dany's guards. When they got angry or wanted to threaten the enemy, gills popped out of their necks. "That idea came from the fruit lizard, which does exactly the same thing, just in a different direction," Martin told Entertainment Weekly. When Danny started riding Drogon, more spikes were added to him