Emi's species were a humanoid alien species who had traveled to other worlds by the mid-22nd century. This species with cranial ridge, pronounced brow and a ridge below the lower lip on the chin.
One was encountered on a moon of Pernaia Prime by the crew of the Enterprise NX-01 in 2152. (ENT: "The Seventh")
At least two members of this species visited the space station Deep Space 9. (DS9: "Prophet Motive", "In the Cards")
Regarding Emi's physical appearance, the script notes emphasized that her character be made up with "minor prosthetics".
Nearly identical makeup was used to create Tria's species
, with exception of a missing chin ridge.