Blerun Downriver was a prominent Southsward otter leader who participated in the Battle of Southsward. He was in command of around one hundred otters armed with javelins. They observed the landing of the crew of the Pearl Queen, but didn't know if they were with or against Urgan Nagru. He found the ottermaid Figgs when she wandered off and returned her to the crew, and he joined forces with them.
They entered Castle Floret using Egbert the Scholar's tunnels, and helped defeat the forces of Silvamord within. They then swept out into Southsward, defeating Nagru and wiping out his rat horde. It is presumed he lived in peace in Southsward after the battle.