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 member of the Order of Maesters, and was in service to House Bolton at the Dreadfort and then Winterfell. He now serves House Stark following 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.

Season 7
Following Ramsay's defeat by Jon Snow in the Battle of the Bastards, Wolkan now serves House Stark, replacing the deceased Luwin, under Jon as the new King in the North. He delivers a message to Jon from Queen Cersei Lannister, addressing him respectfully as "Your Grace". He later hands Jon another message, this one from Samwell Tarly from the Citadel in Oldtown.

After Jon leaves for Dragonstone to meet with Daenerys Targaryen, leaving Sansa Stark in charge, Wolkan discusses Winterfell's food rations with Sansa, Petyr Baelish and Lord Yohn Royce, agreeing with Sansa that there is currently not enough food to feed the North if the battle against the Night King starts soon. Wolkan promises to refer to Maester Luwin's notes regarding the longest winter in the past century and to obtain more food for the North.

Wolkan later builds a wheelchair for the returned Bran Stark, so that he can move around Winterfell more easily. Meera then asks about it, claiming it as a good idea.

Personality
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. With Ramsay now gone, however, Wolkan appears much more comfortable serving Jon Snow and House Stark.

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.