How to find Bloodborne PS4 Moon Presence and all Four Umbilical Cords
In PS4's Bloodborne Moon Presence is a secret boss which if defeated successfully will give you the Childhood's Beginning trophy which is ultra rare. To defeat this Secret Bloodborne Boss, you must first find three Umbilical Cords.
In Bloodborne you have a total of four of such Umbilical Cords which you can collect, but one of them is comparatively harder to find, so you can use any three of the four Umbilical Cords.
How to get all Bloodborne PS4 Umbilical Cords
Umbilical Cord Location 1
You will get the first Umbilical Cord from "Mergo's Wet Nurse" boss when you beat her, this is what she will tell you: "Every Great One loses its child, and then yearns for a surrogate. The Third Umbilical Cord precipitated the encounter with the pale moon, which beckoned the hunters and conceived the hunter's dream."
Umbilical Cord Location 2
Go to the Cathedral Ward and in the Old Abandoned Workshop to find the second Umbilical cord.
Umbilical Cord Location 3
The third cord is in the clinic where the game begun, you can reach this place from the Forbidden Woods later in the game. You will find a women on the upper floor of the clinic, kill her in order to get the third Umbilical Cord. If you have just started the game, you will not come across this cord. You need to come back to get this cord, so remember to collect these items in the same order.
Umbilical Cord Location 4
You will have access to this cord only if you have not yet defeated Vicar Amelia boss. Before you reach Vicar Amelia go and talk to Arianna, who is in the the Cathedral Ward area, behind a door in the alleyway. After you talk to her send her to the Cathedral ward. After killing Mergo's Wet Nurse she will give birth to a child in the basement of the Cathedral. You need to kill the child to get this fourth Umbilical Cord.
How to find Bloodborne Moon Presence
Finding Moon Presence will be very easy once you have three Umbilical Cords with you. Now all you need to do is defeat Gehrman. These two things will trigger a fight between your hunter and Moon Presence.
Defeating this secret boss is not difficult, try to be behind her all the time, you will get enough chances to attack. In case you die, you will appear in the Hunters dream and you will not have to fight Gehrman again to defeat Moon Presence.