Just like the original series, HBO seems to be having a hard time keeping the production of Game of Thrones Prequel a secret. After Naomi Watts' in-character snap emerge online, a new set photo is now circulating on social media, teasing the sigil of one of the houses.

Twitter user GoTlikeLocation revealed a photo of the show's pilot while filming in Gaeta, Italy. Here, fans can see a group of actors wearing their costumes while on a boat carrying a banner of what-looks-like the Starks' sigil. However, this one seems to be a tamed direwolf compared to their angry and brave seal.

"Only shortly before sunset the prop boat came out of the grotto again to go back to the production's second base in the port of Gaeta," the caption read. "This time the boat's crew was in costume, and the banner (which might be an early Stark one?) revealed."

George R.R. Martin earlier revealed the Starks would be a part of Game of Thrones Prequel, along with direwolves and mammoths. "The White Walkers are here - or as they're called in my books, The Others - and that will be an aspect of it," the famed author told Entertainment Weekly. There would also be direwolves and mammoths. 

However, ScreenRant noted the sigil looks like more of a feline than a canine - specifically a lioness. In the show's mythology, the first Lord of Casterly Rock killed a lioness that attacked his village. However, he spared the life of its cub, setting it free.

This small act of kindness pleased the gods, who led him to a pot of gold, giving their family great wealth. Hence, the house sigil maybe a lioness of the Casterly Rock and not a direwolf of the Starks.

It has been known that the Casterlys will play a significant part of Game of Thrones Prequel. First set photos even revealed Watts' character, who believed to play the role of an important member of the said house.

In the snap, the 50-year-old character was wearing a posh dressed, which fits her character description of a charismatic socialite. She was being ushered by two people, who believed to be the show's staff members, while a big sign of "Grotta del Turco" was seen behind their back.

HBO may finally reveal official details about the show soon, so stay tuned here on Business Times for more updates. Game of Thrones Prequel is expected to be out either in 2020 or 2021.