The Tartlo of Basque mythology is a one-eyed giant with a predilection for flesh, specially if it is human and Christian. An inhabitant of the underworld, hell according to religious tradition.

The Tartalo is considered the first shepherd of the caves, where in addition to hoarding large flocks, he devoted himself to his favourite pastime: throwing stones from one mountain to another. There was no human who did not notice his presence.

Other name he is known by is Torto, and he is distinguished from other giants, particularly the kindly ones, because one of his limbs ends in a round, ball-like protuberance.