|Sources: World of Warcraft: Cataclysm|
Merciless ones are aquatic parasitic aberrations in all likelihood related to faceless ones. They are cycloptic, squid-like creatures with a body shape similar to Ozumat. They attach themselves to the heads of things to enslave them, and can affect their host's mind even when "dead." As the Beak of the Merciless One shows, they have beaks.
In the present, the Merciless were first seen during where they were recruiting/possessing gilblins for the assault on the Abyssal Maw. In , it was shown that a Merciless still carries the will of the Old Gods even when its physical body dies. Following Neptulon's capture in ,Erunak Stonespeaker was abducted by the Naga and enslaved by the Merciless one Mindbender Ghur'sha within the Throne of the Tides. In the Twilight Highlands, the giant Merciless one Julak-Doom is controlling a flesh giant.
On an alternate Draenor, there are creatures identical to Merciless known as Amorphic Cogitators who not only posses sentient beings, but leap from humanoid to humanoid to "learn" as much as possible from each one in order to "evolve." During , these creatures are seen possessing and attacking goblins, ogres and pale orcs.
- , controlling Erunak Stonespeaker in the Throne of the Tides
- <The Eye of Zor>, controlling a flesh giant in Twilight Highlands
- Deep Subjugators, summoned from the depths, or somewhere even more unknown, during
- Merciless Ones, controlling gilblins and working with naga on Deepfin Ridge, at least one was later used as a hat
- Jiao Spawns
- Amorphic Cognitors , seen attacking creatures near the Zangar Sea in the Spires of Arak
As a companion pet
- The uses the merciless one model, but is considered to be a sha nonetheless.
- The merciless ones resemble unarmored Daleks from the popular British science fiction program, Doctor Who.
- They may be a cousin species to the Faceless Ones, also an ancient aquatic like species who serve the Old Gods.
- They may also be related to the kraken. Ozumat is a kraken, but given his ability to attach to victim's heads and control them, he is also thought to be a large variant of merciless one. Also, the Jiao Spawn of Jiao are merciless ones (which is likely not just model re-usage due to the spawns' telekinesis).