The son of a Prince of Day and Mariah Cappella, a witch from Speckle Frew, Finnegan was a young would-be hero who was engaged to marry Princess Boa, before she was killed at the altar by a dragon acting under Christopher Carrion's orders. Finnegan set out to interrogate the dragon's family, hoping to discover the truth behind the assassination, but this quest devolved into a crusade wherein Finnegan exterminated whole families of dragons in revenge for the loss of Boa.

He is discovered by several former companions of his and persuaded to join their search to rescue Candy. He is described as a young man having dark skin, red hair, and green eyes; illustrations of him corroborate this and show his hair, which is in dreadlocks, radiating around his face like a halo.