Yert was a Moriok from the Mephidross on Mirrodin.
Yert had orders from Geth to kill Glissa Sunseeker during her trip into the Dross. When Glissa, Slobad and Bosh slaughtered Yert's Reaper, a very powerful zombie, Glissa felt sorry when Yert broke down crying as a result. Yert agreed to help her achieve her goals so long as she would help him get a new zombie to control. Geth, angered at Glissa's impertinence, ordered his pet vampire to attack, which she defeated after grievously wounding it. With no choice, Geth told Glissa what she wanted to know which got her to leave more quickly. Unfortunately, the vampire's wounds were severe and only an extensive feeding would save it. So Yert was fed to the vampire, ensuring the traitor's death. He did not stay dead, unfortunately, and rising as a vampire himself he overthrew Geth after beheading him.