A character in the Norwegian Tristrams Saga. He was a nobleman who lived in a castle by the sea in France. His name was a misnomer; he was in fact a giant.
His wife was kidnapped by the evil Estout l’Orgillus of the Castle Fer. He traveled to the Blanche Land to find his famous namesake, and to ask him to help rescue his wife. Tristan agreed, and the two Tristans met Estout and his brothers in combat. They were victorious, but Tristan the Dwarf was killed and Tristan was mortally wounded with a poisoned sword.
His counterpart in a Icelandic version is Tristan the Stranger.
Sources
Tristan | Thomas of England, 1170-1175
Tristrams Saga ok Ísöndar | 1226