This Ferengi costume was used to portray two different characters in this series: 'Gral' was a Ferengi businessman who traveled to Deep Space 9 in the episode 'The Nagus' so he could hear the Grand Nagus Zek announce his successor. Even though he initially opposed the selection of Quark as the new Grand Nagus, he offered up his services to Quark as his personal bodyguard in exchange for premium opportunities in the Gamma Quadrant. What he offered as 'protection', was intended as a threat.
'Lonzo' was a card shark whom got played by Odo as 'Curzon Dax' in the episode 'Facets'. 
Gral was portrayed by Lee Arenberg, but in a highly odd contradiction to practice, there are no tags in any piece of the costume to denote this. However, every piece does have the name Mark Barrett, which would suggest that Lonzo was portrayed by him. This costume also makes several guest appearances in DS9. It can be seen briefly in the episode 'Family Business' and was also seen hanging in Garak's shop in 'Profit And Loss'. 
Lastly, we see it draped over Quark's sofa in 'Prophet Motive' 
Update 10/20/14: I finally got to meet Lee Arenberg at the Las Vegas Star Trek convention in 2014. He was as generous with his time as he was funny.%2B(640x458).jpg)