From: Star Trek: Deep Space Nine
Caption: Maihar'du, a Hupyrian male servant to the Grand Nagus Zek
Planet: name unspecified. A tall, facially-wrinkled, white-skinned, mute, humanoid species, many members of whom can be found working for important Ferengi officials because the Hupyrians have a wide-spread reputation for utter devotion and loyalty to their employers. In fact, those who become servants take a vow only to speak to their masters.