Thermund

Thermund  is a warrior in the service of House Forrester.

Background
Like Norren, Thermund serves in the Northern army, and fought at the Battle of the Whispering Wood.Thermund appears to be friends with Norren or at the very least known him before the events of the Red Wedding  as he joked around with him about Norren claiming to had a large part in capture of Jaime Lannister.

"Iron From Ice"
Thermund is seen outside The Twins with the other House Forrester Warriors drinking alcohol and having fun during the Wedding. Thermund begins to questions Norren's story about him having a hand in capturing Jaime Lannister and playfully makes fun of him.

When the Red Wedding slaughter begins Thermund is one of the first House Forrester warriors to killed, Thermund is killed by an unnamed Frey soldier.