Wolkan

"My lords. Lady Walda has given birth. A boy. Red-cheeked and healthy."

- Wolkan reporting the birth of Roose and Walda's son.

Wolkan is a recurring character in the sixth and seventh season, though is first mentioned in the fifth season. He debuts in "The Red Woman," and is portrayed by Richard Rycroft. He is a member of the Order of Maesters, and was in service to House Bolton at the Dreadfort and then Winterfell. It is currently unknown if he still serves at Winterfell now that it has been taken back by House Stark and House Bolton is extinct after the Battle of the Bastards.

Season 5
At dinner, Lord Roose Bolton reveals to his family that Lady Walda is pregnant, and that Maester Wolkan believes the child is a boy.

Season 6
Wolkan listens as Ramsay recalls his initial interaction with Myranda. Wolkan asks Ramsay whether to bury her body or burn it on a pyre. Ramsay tells him to feed it to the hounds.

Wolkan later informs Roose of Lady Walda's birthing of a boy, and subsequently witnesses Ramsay kill Roose, his own father. Terrified by what has happened, Wolkan obeys Ramsay's order to inform the Northern houses that Roose was poisoned by the Boltons' enemies. Ramsay then instructs Wolkan to bring Walda and the baby to him. Wolkan tells Ramsay that Walda is resting, his own way of subtly pleading for their lives, but Ramsay's glare scares Wolkan into obeying.

Wolkan's status following the Battle of the Bastards and House Bolton's extinction is currently unknown, though it is possible that Jon Snow has appointed him to replace Luwin as House Stark's maester.

Personality
Unlike most members of House Bolton, Wolkan is shown to be a peaceful man who abhors violence, shown when he is visibly shocked at Ramsay murdering his own father in cold blood, and doing his best to plead for Walda and her baby's lives when he knows what Ramsay intends to do to them. Also, despite her vicious and sadistic nature, Wolkan appears saddened at Myranda's death and even more so when Ramsay instructs him to feed Myranda's body to the dogs instead of cremating or burying her with dignity, even though Myranda had no dignity to speak of in the first place. This appears to be due to Wolkan's training as a maester, to generally help people instead of harming them in contrast to the likes of Myranda, Locke and the Master Torturer. These traits may convince Jon Snow to appoint Wolkan as House Stark's new maester to replace Luwin.

In the books
In the A Song of Ice and Fire novels, there is no character named Wolkan. Lord Roose Bolton brought three maesters to Winterfell to be put in charge of the ravens and messages, not to look after Walda. They were Maester Henly from Blackpool, Maester Medrick from Hornwood and Maester Rhodry from Castle Cerwyn. In the sixth season, Roose refers to "the maesters", indicating that Wolkan is not the only maester who serves the Boltons in Winterfell, but since Wolkan is the only one shown or named personally, it is possible that he is the head maester.

Maester Wolkan is apparently named after one of the TV series's co-producers, Annick Wolkan.