Bert

"He's the fat one. He's on guard duty tonight. He likes to drink wine and sleep a lot"

- Princess Shireen Baratheon

Bert is an unseen character mentioned in the third season episode "Kissed by Fire". He is a guard of House Baratheon of Dragonstone serving in the dungeons of the castle.

Background
Bert is fond of wine.

Season 3
Taking advantage of Bert falling asleep while drunk with wine, Princess Shireen Baratheon visits the imprisoned Ser Davos Seaworth.

In the books
In the A Song of Ice and Fire novels, there is no character named Bert.