Wolkan

"From the way she's carrying, Maester Wolkan says it looks like a boy."

- Roose to Ramsay Bolton

Wolkan is an minor character in the fifth, and sixth seasons appearing first in "High Sparrow". He is a member of the Order of Maesters, and is in service to House Bolton at Winterfell.

Season 5
Wolkan assists Bolton men with moving ravens into his new quarters.

Wolkan diagnoses Lady Walda Bolton as being pregnant, and expresses his belief that the child will be a boy.

Season 6
Wolkan listens as Ramsay tells of 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.

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", hinting that Wolkan is not the only maester serving the Boltons in Winterfell.