Ser Walder Plumm was a knight of King Trystane Baratheon's Kingsguard
History
He was brought onto the Kingsguard and died of a chill during the Great Winter Frost.
Himself, Ser Pearse Tyrell, Ser Addam Bar Emmon, and Brave Ben Fields had a very close fellowship as they served through much of Trystane's peacetime rule together.