Richie "The Hammer" Ginelli (first appeared in Thinner)

An underground mobster who helps Billy find the gypsies and convince them to remove his curse.

Richie "The Hammer" Ginelli is mentioned in the following books:

The Dark Tower II: The Drawing of the Three (May 1987)

Rico Balazar is involved with a thug named Ginelli.

Ginelli. There was only one Ginelli Eddie knew; he ran a restaurant called Four Fathers. The pizza business was a sideline, a guaranteed stiff, an accountant’s angel. Ginelli and Balazar. They went together like hot dogs and mustard.
- The Prisoner / Chapter 4: The Tower