Jon Snow and his direwolf Ghost in Game of Thrones go to together like peanut butter and jelly. Considering that Ghost has proven to be fiercely loyal to Jon and a fearsome combatant in previous seasons, it seemed a little strange when he didn't make an appearance during season six's massive battle for Winterfell.

It turns out there's a reason why Ghost wasn't shown ripping into the Bolton army: Wun Wun the giant, or more specifically, how much Wun Wun cost to bring to life. CGI characters aren't cheap or easy to bring to life, so the showrunners had to choose between depicting Jon's direwolf or one of the last living giants during what proved to be one of the show's most impressive action sequences to date.

"[Ghost] was in there in spades originally, but it's also an incredibly time consuming and expensive character to bring to life," episode director Miguel Sapochnik says to Business Insider. "Ultimately we had to choose between Wun-Wun and the direwolf, so the dog bit the dust."

Sapochnik goes on to describe the difficulty of working Wun Wun into the events of the show.

"Anything with the giant is a challenge," Sapochnik says, "because he's not there, and you have to shoot multiple layers for each shot, and get extras to react to something that doesn't exist, and then shoot the actual giant played by Ian Whyte months later on a green screen stage."

Though Ghost didn't get the chance to shine at the battle, fans did see the direwolf earlier this season as he guarded Jon's lifeless body from those in the Night's Watch looking to kill the supporters of the momentarily-dead Lord Commander. Wun Wun ultimately sacrifices his life for Jon and the Wildling army, breaching the gates of Winterfell in order to bring victory for the Starks.

Perhaps with Wun Wun's death, fans can expect to see more of Ghost in action. Jon and Ghost are nearly inseparable in the Game of Thrones book series, but that obviously hasn't been the case on the show, where the CGI Ghost proves to be a costly addition. It does, however, seem like the show's budget only continues to grow, so here's hoping Ghost will get his moment in the spotlight in the few seasons left to come.