Deyos was a Vorta in the service of the Dominion. He was the commander of Internment Camp 371 in 2373.
When the Cardassian Union joined the Dominion, Deyos released all of the Cardassian prisoners being held in the camp with the exception of Elim Garak, whom he was ordered not to release by Gul Dukat.
When Ikat'ika refused to kill Lieutenant Commander Worf in combat, Deyos ordered both to be killed. Ikat'ika was vaporized by his fellow Jem'Hadar, but Worf was beamed aboard a runabout. (DS9: "By Inferno's Light")
Deyos was played by Ray Buktenica.
According to the script, the Vorta name's was pronounced as "DAY-oss".