Eltas

Eltas was a man of Tol Eressëa whom Eriol met at the Cottage od Lost Play where Eltas recited the Story of Túrin Turambar and Glaurung.

Speculations
Although it is not explicitly mentioned Eltas seems to be a mortal man rather than an Elf.This would mean he was another man from the East who had stranded on the Island prior to Eriol, though he also might have been one of the Eneadurians.