Deimos was an Eevee Jared caught at level 19 in Part 12. Deimos was actually a challenging Pokemon to catch, breaking out of a Great Ball at 3 and only 1 of an Ultra Ball, both while at only 10% of health left. Despite Jared's enthusiasm of obtaining Deimos, he wasn't introduced until later on in the episode after Chompit met her fate.
Deimos participated in 4 battles, with only one being successful, defeating Psychic Sayid's Kirlia solo. He was the first to challenge Rising Star Manon's Lunacone, but only did minimal damage until he was switched out. He also fought against Psychic Emanuel's Solosis, but almost died from Hidden Power and was immediately switched out before he had a chance to attack. In the end, Deimos met his fate to the hands of Brains & Brawn Frank & Sly's Machoke, the same one who took out Teeckadee later on in the fight.
Deimos shares his name with the moon of Mars, suggesting that Jared may have hinted he would evolve him into an Umbreon if he had the chance.