The Bloodletting Beast is a gigantic hulking creature. Its back has been split open and its face is heavily scarred and mutilated, although its still retains a humanoid shape. Even with its colossal size, the beast is capable of stretching its arms to reach opponents and its attacks are incredibly fast.
In the Pthumeru Ihyll Chalice Dungeon, a even more mutilated version of the beast can be encountered. This version lacks a head, although this does not impair its vision, and it is capable of launching parasites out of the wound on its back. When low on health, a gigantic parasite worm will replace its missing head and attempt to bite opponents, inflicting rapid poison.
The Bloodletting Beast is an extremely aggressive opponent and will constantly attempt to close in on the player to initiate its attacks. Whilst it is tempting to attack the boss from underneath, it will retaliate with foot stomps or a deadly grab attack so its recommended to stay in front of the beast whenever possible. Most of its attacks have an alarming range, especially its lunging punch that can easily instantly kill a player if not evaded perfectly. The Bloodletting Beast will often end its combos with a lunge, slam or bite attack so the player should ensure that they always have room to evade backwards. The Headless version has a long range projectile attack where it fires parasites at the player, these are easily evaded but inflict rapid poison if hit.
Inflicting enough damage to the Beast's arms will stagger it, leaving its head vulnerable to visceral attacks. It will often pause to heal its arms which offers another opportunity to attack its head. This tactic can also be used against the Headless version.
During the second phase of the fight, the Bloodletting Beast will no longer heal its arms and will become even more aggressive, its combos become longer and it rarely pauses between attacks. The Headless version will grow a massive worm parasite to replace its head which rapidly inflicts poison if it bites the player.
Both versions of the Bloodletting Beast are very vulnerable to fire damage, and it is recommended to bring as any items as possible that inflict this such as Oil Urns, Molotov Cocktails and Fire Paper. It is also recommended to save these items until the 2nd stage of the fight where it becomes much more risky to attack the boss at close range.
-  was a medieval practice where it was thought that illnesses could be released from the body by bleeding the afflicted patient. It is similar to Yharnam's practice of Blood Ministration.
There are two versions of this boss.
The normal version:
The worm head version: