Scar-Tail is an Argonian assassin and shadowscale hiding out at Bogwater camp after fleeing Black Marsh and refusing to carry out his duties as an assassin. He, Teinaava, and Ocheeva grew up together as they trained to be shadowscale assassins with the Dark Brotherhood.
"When Ocheeva and I trained with the Dark Brotherhood as children, we befriended another initiate, a Shadowscale by the name of Scar-Tail. The three of us were inseparable. When our training was completed, we reluctantly parted ways. But now... Now, the unthinkable has happened! Scar-Tail has fled Black Marsh and refuses to fulfill his duties as royal assassin! This is an act of treason! This treachery must be punished!" -Teinaava
"I guess I've been expecting you, assassin. Don't try to deny it. I can see it in your eyes. You're Dark Brotherhood through and through. Let me guess, it was Ocheeva, right? No, wait. Teinaava. Yes, he put you up to this, didn't he. Ocheeva was always too busy to even be bothered. Well, you can kill me if you like. I'm afraid I won't make much of a challenge, though. The Argonian Royal Court already sent an Agent to do the job. He failed, of course. His body's around here somewhere. But he got in a pretty good hit. If I don't get some rest I'm probably dead anyway." - Scar-Tail