Father, originally known as Homunculus, is the first homunculus and a living philosopher's stone, created from Van Hohenheim. Father has gone by multiple names including, The Philosopher of the East, The Dwarf in the Flask, and The Good Gentleman. He is the lord of the seven homunculi who all refer to him as "Father" because he gave them life and created them. He has spent centuries controlling the country of Amestris from behind the scenes, towards the goal of sacrificing all the living things to rip open the Gate of Truth and absorb all the power it contains to become the new God.
- At the beginning when he was only name "Hounculus", Father looked like an orb of dark sand-like matter, (which is apparently pure, physical knowledge) who could form an eye, a grinning mouth and some small tendrils.
- After becoming a living Philosopher's Stone, he used the DNA from Van Hohenheim to create a body with which he could use to interact with the world more effectively. The body having been made with Van Hohenheim's DNA as a base, the body was completely identical to him.