Slavers (yssgalahl is an approximate rendering of their autonym) are aquatic sophonts who look vaguely like 4 m long mucus-covered catfish with tentacles. They are a psionic species who use their abilities to stun prey in their native oceans. The Slavers never developed more than rudimentary tool use until human explorers visited their world, and they discovered that off-world organisms have little resistance to their abilities.
Only the sheer size of galactic civilization, their aquatic nature, and the resistance of other psi-capable species kept them from establishing a vast empire. Instead, they became slave traders.
They keep a number of personal servants and sell the rest on the galactic market-places where “naturally” grown sophonts are preferable to Bioroids or robots. The Slavers are the primary suppliers of Minga slaves.