The offspring of a devil, typically an incubus or succubus, who exist for this purpose, and a human; these children are almost invariably evil, although a timely baptism will drive out the Satanic influence — a handy mediæval argument for infant baptism, as well as an assertion that Christianity depletes the ranks of the evil. Mediæval literary examples are overwhelmingly children of incubi, or Satan himself, and mortal women. Because a demon is an imperfect creation and cannot beget life, the child is born seeming in all ways dead, except for the circumstance that it lives; this condition persists until its seventh year, at which point the child is indistinguishable from a normal person. From this point it begins to use its devilish cunning to sow discord and indulge its thirst for power and sin.
Sometimes the cambion child will be unnaturally large at birth, or grow rapidly, or be born with the power of speech; Merlin, in the so-called Prose Merlin, is said to be immensely hairy. These are traits the cambion shares with its irreligious cousin the changeling; we may assume cross-pollination, although which way it has gone is impossible to tell. Cambions normally have supernal powers to enable their wicked ways, particularly that of shape-changing — which is fitting, as it is an ability proper also to their most common infernal parents.