Tubal

Shylock's fellow moneylender

Tubal is a wealthy Jew of Venice, who lends Shylock enough to make up the full three thousand ducats the latter lends to Antonio. 

Shylock sends him to track down Jessica, though he is unable to do so, only being able to make a list of all the bills she has run up over the course of her flight. He also brings Shylock news that Antonio is on the verge of bankruptcy.