The Abyssal is a massive, worm-like Remnant construct that inhabits the deserts of Elaaden. It is even larger than an Architect, and can be seen and heard moving from as far away as New Tuchanka. It is non-hostile, but also cannot be killed. The Abyssal's function as a Remnant machine is unknown.
Over several months, the Nexus has received numerous unconfirmed reports of a huge Remnant construct in the Elaaden dunes. It is said to patrol a certain area of the desert, diving through the sand seemingly unimpeded and attack intruders with overwhelming force. As no trace of such a construct has been found, and these witnesses are often found to be suffering from heatstroke, the Nexus is currently dismissing these claims as a "white whale" myth. Those who believe the reports refer to these constructs as "Abyssals."
If the reports are in fact accurate, the question arises as to the Abyssal's purpose. Such a construct might be used to extract and process valuable resources from the sand, using the kinetic pumping action to power it. Alternatively, the Abyssal might be used as a defensive measure for sensitive locations. Regardless, the reports all state that the Abyssal is impervious to weapons and indifferent to communications, suggesting that if it actually exists, this construct would be best studied at a distance.
- The Abyssal's Codex entry can be unlocked by speaking to a "Colony Krogan" in New Tuchanka who talks about the machine.
- The Abyssal will move in a set sequence of jumps, always emerging and hitting the ground in the same spots. One can use this to get close to it, despite it moving faster than the Nomad.
- The Abyssal cannot be scanned, being hit by it in the Nomad produces an explosion visual and no other effect, and being hit by it on foot will instantly incapacitate crew and kill Ryder.
- Several krogan colonists in New Tuchanka can be heard talking about "The Worm" and even ponder it as an alternative for a Thresher Maw in the Rite of Passage.
- The Abyssal can actually be seen as two distinct and separate units, one red and the other blue, jumping in tandem with each other. The red one is longer and larger than the blue one.
- The sand dunes of Elaaden coupled with the giant worm-like constructs and the lack of water may be a reference to Frank Herbert's book "Dune" that was made into two separate movies.