Who is Tapper John

My name is Twaag Joon, I was born in the dark tunnels of Quarmall. I was Sold as a slave to a kind merchant in Lankhmar more that 40 years ago. The Merchant Died of old age leaving Twaag homeless in the City of Lankhmar. I have been a security guard for merchants for the last two years. I have work for the Thieves guild as a Bravo, and would like to gain a permeant position in the guild.
Tapper John is my street name, it was given to me by the old merchant, his name was Tolly Brighthair. Tolly said that when I was young I would continuously tap on my chains, which he later removed.