Firstborn Son - The Binding of Isaac

Random item

▾Table of Contents▾

Firstborn Son is an unlockable familiar in Furtherance, a mod for The Binding of Isaac.

When in an uncleared room with enemies, will turn into a homing exploding ghost similar to Purgatory one.

The ghost will target the enemy with the folowing priorities: Non-bosses over bosses > Highest health > Closest to the ghost.

Will instantly kill the targeted enemy and does not damage other enemies. If targeted enemy is a boss, deals 10% of their maximum health instead.

Defeat Mother as Miriam

This item contributes towards the

Conjoined transformation. Collecting 3 items from this set will make Isaac shoot in 3 directions at the cost of -0.3 damage and -0.3 tears.

Firstborn Son can be found in the following item pools:

Name	Weight
Treasure Room	1.0/1.0
Greed Treasure Room	1.0/1.0
Baby Shop	1.0/1.0

The following tags are applied to this item:

Id	Description
baby	Contributes towards the Conjoined transformation.
uniquefamiliar	Cannot be duplicated via Box of Friends.
offensive	Can appear for Tainted Lost.
summonable	Can be summoned via Lemegeton.
monstermanual	Can be summoned via Monster Manual.