Claret is a character version of the "Spirit of the Harp" card, who appears in the alternate dimension in Yu-Gi-Oh! GX.
Claret lived in the same village as Burgundy and Nero. After Burgundy knocked out Jim Crocodile Cook, believing him to be a minion of The Supreme King, Jim's unconscious body was taken to Claret's hut, where he regained consciousness. When he did so, Burgundy asked Jim and Axel Brodie to stay in the village to hide from the The Supreme King and help defend it when the attack came. Jim and Axel declined, intending to journey to the King's keep, believing that Jaden Yuki is being held captive there. As they leave, Burgundy and Claret conversed, and Claret states that there's still a chance that Jim and Axel could create a miracle. Shortly thereafter, the village is attacked and destroyed by The King's Army.