The species known as the Unstul was first encountered in 15 ABY, and are native to the planet Amistel. They resemble large, blue jellyfish, consisting of a large cube that functions as head and body, with four sets of eyes. Four breathing holes surrounds the eyes, two above and two below each set of eyes. Six long tentacles and eight shorter tentacles erupts from beneath the cube, the short tentacles sporting vicious hooks. They have no visible mouth. They evolved from omnivorous jellyfish, but were forced onto land after a natural disaster destroyed their homes. They soon adapted and are now effectively amphibious. They speak Basic to non-Unstul, as their own 'language' consists of their tentacles moving in intricate patterns, conveying meaning that way. Unstul also possess the ability to use limited telepathy, conveying and reading thoughts. However, even the slightest mental resistance will prevent the alien from reading the thoughts of the subject.
The Unstul sports two types of tentacles. The long ones act as hands and conveys their language. The short ones are used for self-defense, sporting vicious hooks that not only tears the flesh, but also injects a powerful neurotoxin into the bloodstream of their victim. Large creatures may just be stunned, while smaller creatures will die within seconds. The actual dose of toxin can be regulated by the Unstul prior to injection.
Unstul are notoriously hard to kill. Not only does their body regenerate nearly any wound, even regenerating lost limbs though the process is slow, but as their nervous system acts as brains they have to be almost entirely disintegrated to be killed.