Meloneus

Meloneus was a gul-level officer of the Cardassian Union. He held an ongoing grudge against Changelings and the crew of the USS Phoenix-X (NCC-75948). 

Childhood
When Meloneus was young, he was very attached to a Cardassian baby toy. One cold and rainy night, while about to board a hover-transport with his mother, two Changelings (disguised as Cardassians) took notice of Meloneus. As they spoke to each other, they spoke as though they weren't Cardassians at all; and they revealed their connection to an alien group known as the Founders. Due to pure fascination, the two Changelings stole Meloneus' baby toy, reverted to their generic Changeling forms, and ran off. Meloneus was left, crying in the rain; thus forever scarred by Changelings for the rest of his life. ("BaKardi Slang")

Commander of the Tarak
Years later, Meloneus became a gul-level officer in the Cardassian Union. He commanded the starship Tarak, with his nephew, Tellus, who was an executive officer. ("Secret Shuttles, Part II")

Sometime before 2374, the Tarak came into conflict with a Romulan starship. It wasn't long before they opened fire on each other, when the USS Xena arrived to aid the Tarak`s distress call. It was at this point Meloneus met Captain Aeris and Commander Gotens, who were commanding the Xena at the time. The Xena was used as a distraction while Meloneus took over the Romulan starship. With this turn of events, Meloneus turned against the Xena, despite the fact they came to aid his distress call. ("Missed the Mishap")

In 2374, Meloneus somehow discovered that Captain Daniel was a Changeling and was prepared to capture him and hold him under an anti-shapeshifting emitter. Meloneus attacked the Phoenix-X and beamed Daniel over, right after the Phoenix-X had beamed over one of Meloneus' men: an officer named Agenos. Gotens contended to a prisoner exchange, where both Agenos and Daniel would be returned to their respective ships. Unfortunately, as the exchange was supposedly going through, Daniel was not beamed back, and both Agenos and Gotens were transported onto the Tarak. In time, both Daniel and Gotens were able to escape thier holding cells and take over the Tarak. Both Meloneus and the ship were then taken into custody. ("Missed the Mishap", "Secret Shuttles, Part III")