Peepo's Pit is a mercenary pit on Karma Space Station, Karma-IV. It is run by Peepo the Veetanho.
From the Books: "They turned a corner and Jim expected another long street teeming with aliens, but instead they entered an establishment. At first he thought it was a bar, but as he looked around he could see their specialty wasn’t intoxicants. The room was lined with hundreds of flat displays, all showing scrolling data. Jim could recognize a dozen languages on sight, and sparingly read three. He didn’t have to stretch his abilities because one of the screens was displaying English, the official language for Earth. He quickly read some of the data and realized it was displaying merc contracts." - Cartwright's Cavaliers, p. 55.