Walks-With-Rushes is an Argonian found with his companion Sanadarin at their campsite at one of their possible locations in Shadowfen. The Vestige can light their fire as part of the Lightbringer achievement.
Upon encountering them:
Walks-With-Rushes: "Light it, then! Or are you afraid to singe your furry tail?"
Sanadarin: "This one's furry tail caught dinner, or have you forgotten? It is you who wanted to cook the meat!"
- "Thank you." – After lighting their fire