Cambion Conception

Cambion Conception is an unlockable passive item added in The Binding of Isaac: Afterbirth.

Effects[]

Upon taking damage a certain number of times, Isaac gains a permanent demonic familiar. Possible familiars include:
- Dark Bum
- Demon Baby
- Incubus
- Leech
- Lil Brimstone
- Succubus
- Lil Abaddon
- Twisted Pair
The first and second familiars will each spawn after taking damage 15 times. The third and fourth familiars will each spawn after taking damage 30 more times. No further familiars will spawn. As a result, after taking damage 90 times, four out of eight possible familiars will have spawned.
Isaac will look progressively more pregnant as he takes damage.

Lilith starts with this item by default, even if it hasn't been unlocked. Lilith can get a second Incubus through this.
Only one of each type of familiar can be spawned.
Familiars that have yet to be unlocked can still spawn.
Only actually getting damage counts towards the payout. For example, negating damage with the Holy Mantle will not count.
Familiars spawned this way do not count towards transformations nor the collection page.
Familiars spawned by the item do not affect item pools, so multiple copies of one familiar can be obtained. For example, a second Incubus can be purchased after Cambion Conception spawns one.
If a familiar obtained is a copy of another one already obtained, using Box of Friends will only clone one of that familiar.
If this item is removed with XVII - The Stars?, it will also remove any familiars already obtained through Cambion Conception.

Dull Razor: Dull Razor counts towards the payout despite not removing health to Isaac.

Caffeine Pill: Makes it impossible to tell how far along the pregnancy is.
Cambion Conception: Having a second Cambion Conception allows the player to get the eight familiars, but cannot give an already obtained familiar.

This item is the demonic counterpart to Immaculate Conception.
In mythology, a cambion is the offspring of a human and an incubus or succubus.
During the development of Afterbirth, Edmund McMillen asked on Twitter^[1] what the opposite of Immaculate Conception would be called. 27 people replied with suggestions, but none of them were used.