Mergo's Wet Nurse is the last mandatory boss in Bloodborne. You may have more boss fights later, but it depends on your story ending.
Reward: One Third of Umbilical Cord. Eat all 3 pcs after this boss fight to get an alternative Bloodborne game ending.
Good luck and Have a nice game!

Bloodborne Mergo's Wet Nurse fight. Bloodborne Mergo's Wet Nurse fight tips.

I am Alex68, my channel gaming and fun alex68acmp: http://goo.gl/zCIqIL
Watch more of Bloodborne: http://goo.gl/8wAcrP

1st boss: Bloodborne Cleric Fight: https://youtu.be/ubsj6SE5G8o
2nd boss: Father Gascoigne: https://youtu.be/aG654IgWiTs
3rd boss: Blood-starved Beast: https://youtu.be/-3HlvHuOJ6I
4th boss: Vicar Amelia: https://youtu.be/cvyHp6Y7iHE
5th boss: The Witch of Hemwick: https://youtu.be/-p_esxJxqJE
6th boss: Shadow of Yharnam: https://youtu.be/qedjfX1phJA
7th boss: Rom, The Vacuous Spider: https://youtu.be/vhVfQ7gdpso
8th boss: Celestial Emissary: https://youtu.be/yUyGj_R0NpU
9th boss: DarkBeast Paarl: http://youtu.be/5_rlDTawW8s
10th boss: Ebrietas Daughter of the Cosmos: http://youtu.be/f5gndQKyb3g
11th boss: The One Reborn: https://youtu.be/DZb1F9fKGGo
12th boss: Amygdala: http://youtu.be/XrhHQgo1XOA
13th boss: Martyr Logarius: https://youtu.be/ZLy887sQYiA
14th boss: Micolash Host of the Nightmare: https://youtu.be/22zHArZBfmI