A Cyrodilic drunken wanderer called Giordan Lupus. He's in the habit of travelling aimlessly while wearing as loose-fitting clothes as possible to have room for many more useless trinkets than he already has. The Ragged Flaggon is where he goes to drown his guilt in brandy and dark humour. He somehow stumbled his way up in the Thieves Guild hierarchy and is now a Nightingale entirely by mistake. He makes an absolute crap job out of it, since while he's deft with his fingers, he probably thinks with the wrong body parts. He is basically much more of a pickpocketing old pervert than a professional thief.
Also a Khajiit called Jubashi who enjoys collecting gems and stealing people's valuables only to return them for a reward and poisoning people's shaving knives to promote hairiness and whose dream would be to spike an Empire official's drink with skooma just before a public announcement. Preferably the emperor himself.