Sirens

Sirens are an aquatic alien race that lives on the planet of Aquamarine, which orbits the star known as Hygierose.

History
The Sirens frequently trade with mercenaries and private organizations to get foreign technology to study, and have deployed several slipspace probes to examine current ongoings; one of said probes was detected by a Spartan during the Invasion on Beta Maximus.

Biology
Sirens are a race of powerful aquatic shapeshifters; they generally suppress their true powers by developing different forms to keep themselves under control. Unlike many other races, Sirens only have one gender, which most claim resembles a female. Sirens are also able to transform and adapt their bodies to the current situation. Transforming is a painful process for Sirens, as it requires them to break down their current form and rework it back up; transforming is a lengthy process, but once completed, every form makes the Siren significantly stronger.

First Form
The first form resembles the Mermaid of Human mythology. It has a humanoid torso and a serpentine lower body, which the Siren can nimbly slither around with. The tail is capable of whipping someone with enough force to kill them, and the form also has razor sharp nails that can be sheathed when outside of conflict. When Sirens have dealings with other species, they are always seen in this form due to its frail and approachable appearance. This form can indefinitely breath underwater.

Second Form
The second form of a Siren is focused on increasing the strength of the individual. The serpent-like features extent from below waist to covering the entire body. In this form, a Siren is capable of lifting up over ten times its body weight, and has enough strength to stop a speeding vehicle. The reaction speed and brain functioning of the Siren is also increased, and the Siren grows natural armor plates around its shoulders and waist. This form can also breath underwater indefinitely.

Third Form
The third form drastically changes the appearance of the individual, and resembles a large crocodile. Already including the boost of the second form, the third form sacrifices the gills and other extraneous body functions, and replaces them with pure cardiac muscles; it also replaces the tail of the other two forms and grows legs. The Siren is extremely fast while in this form, and can outswim any known aquatic vehicle. The immense speed is maintained on land, and the Siren can sprint at speeds of up to 80 MPH. The third form has large claws, as well as forming jaws with blade-like teeth. They lose their pupils, and also take on a somewhat hunched position while on land. Due to the sacrifice of the gills, the Siren is still able to hold its breath for extended periods of time, but not indefinitely like the previous forms.

Fourth Form
The fourth form is said to be the most powerful incarnation of the Siren, since it combines all the best aspects of the previous forms. No living being today has ever seen a Siren in its fourth form.

Technology
Sirens utilize a mineral exclusive to their home planet as their primary source of energy. They've built aquatic skiffs, and large bio-domes underwater, to name a few inovations. Their space vessels are can be flooded with water to allow comfort when traveling, and their armaments for ship-to-ship combat include electric wave generators, and electric torpedos.