Trellia appeared for the first time in Ecco: The Tides of Time. She is a member of the Skyfin dolphin species of the future.

She travels to the past to inform Ecco of the split that has occured in the timestream. After this she brings Ecco with her to her time. Unlike the dolphins of Ecco's time, she seems to have the ability to time travel at will.

She states that she is one of Ecco's descendants,from about ten million years in the future. Even though she is from the "good" future, both she and the contemporary Asterite somehow have knowledge of the split and multiple timelines. After bringing Ecco to her time, she fulfills no other further role and is never seen again.