Sea squid were organic life-forms found in the Pit and used as weapons by the Barraki. Sea squid hatched from eggs and came into the world hungry, and their preferred diet was the life energy of other beings. They attacked by latching on to their prey with an almost unbreakable grip and then draining the energy directly. Kalmah discovered the cave that acted as their hatchery and began keeping them from food and abusing them to ensure that they would always be hungry and aggressive. He then created mechanical launchers that could be used to hurl the squid swiftly at a target. All six Barraki carried these launchers.1
Notes
When a squid attacked a target, it drained the target's life energy. Each Barraki had added a special feature to his armor that allowed him to clip living squid on and carry them as ammunition.2
The Octo Cave located on Mahri Nui's landmass was the source of Kalmah's sea squid, which plagued the Matoran of Mahri Nui for a long time.3
Sea squid were small, nasty creatures bred by Kalmah. The Order of Mata Nui did not discover how Kalmah bred them. Unlike other sea creatures, which simply fed off the bodies of other creatures, sea squids fed on the life force of their prey. When a sea squid attached itself to another living thing, the suckers in its tentacles began to draw out the energy of the victim. If the squid was not torn off in time, the prey would die. This brutal method of survival made the sea squid seem like an evil creature. Kalmah was responsible for much of the sea squids' vicious behavior, as he made sure to keep them hungry and hostile. Kalmah designed a mechanical launcher which could be used to hurl sea squids at enemies. All six Barraki came to carry this weapon.3
Like other sea creatures in the Pit, air was toxic to the sea squid. Although small, they were incredibly strong, requiring great effort to detach.3
If a squid was removed from its host before leeching all of their life force, the host could regain the energy over time.4
Removing an attached squid was pretty difficult to do.5
Sea squid were vampiric, essentially absorbing life energy from beings the same way Matoran absorbed energy from fruits and caught Rahi.6
The Great Temple Squid was not related to Kalmah's giant squid or the vampiric sea squid.7
Blue squid had no special powers.8
There was no difference between blue and orange squid.9
Vampiric squid weren't very intelligent.10
Launched squid were either retrieved by Kalmah or left to wander and feed or get killed by larger sea predators.11
Organic Nature
Squid were organic and native to the ocean around Voya Nui.12
Sea squid were native to the waters around Voya Nui.13
Squid were organic and not native to the Matoran universe.14
Sea squid were creatures, but they weren't biomechanical and were unfamiliar to Matoran, so they might not have been considered Rahi.15
In the eyes of the Matoran, squid were Rahi because they weren't Matoran. However, squid weren't biomechanical.16
Sea squid were creatures, but they weren't biomechanical and were unfamiliar to Matoran, so they might not have been considered Rahi.17
Squid, as with all organic creatures, came into being the same way Earth creatures did.18
Sea squid were native to the waters where mutagen was present unlike the biomechanical beings. It's possible the mutagen's effects were much more subtle on fully organic beings than they were on biomechanical ones, or it may have been that they took much, much longer to manifest.19
Barraki Usage
Kalmah didn't produce the squid, they were purely organic and hatched from eggs.20
Sea squid were a separate species from the giant squid commanded by Kalmah.21
Not all of Kalmah's squid were red, orange, or yellow.22
Squid didn't swim very fast compared to how fast they were when launched. 23
Squid were trained not to attack the Barraki.24