Which Tolkien character is also known as Eärendil the Mariner?

The Tolkien character known as Eärendil the Mariner is Eärendil.

Eärendil is a Half-elven hero of the First Age and the central figure of one of Tolkien’s major legends. He sails to the Undying Lands to seek help from the Valar for the peoples of Middle-earth during the War of Wrath against Morgoth.

With the aid of the Silmaril carried on his brow, Eärendil reaches Valinor. He later becomes a star-like light in the sky, and his story connects the ancient mythology of The Silmarillion with the small phial of light that Galadriel gives Frodo in The Lord of the Rings.

Eärendil is the father of Elrond and Elros. Elrond chooses the fate of the Elves, while Elros chooses that of Men and becomes the first king of Númenor. This family history is why Eärendil is important across several ages of Tolkien’s legendarium.