The Ljynii
Very little is known about the enigmatic Ljynii, even their appearance. They are supposed to have five limbs, not including tail, with arms that split into two at the second elbow. They seven digits on each hand, with two double-jointed thumbs. Their heads are long, apparently with some form of snout at the tip.
No two of their ships look the same, but
usually follow the same type of harshly-angled design. They are
larger than most Type A astronomical bodies, and some are larger
than Type B's as well. They carry up to three million soldiers
and have extremely powerful unknown weaponry. They are very
rarely seen in the Jotun Empire at all, except when they attack,
and are usually confined to one system in their home galaxy,
Phaerun (Shee for 'very scary').
The main part of the Ljynii population live on the Linkworld, an
immensely large artificial structure consisting of two
interlinked torii. Each torus is large enough to have a sun orbit
around inside and for the inner wall to have a temperature not
that different to Midgard. Each torus is populated by a number of
Ljynii so vast it cannot be calculated without the use of many,
many zeroes.
No one is really sure why the Ljynii seem intent on attacking the Jotun. It may be to do with the Shee, but since none remain in the Empire the question cannot be answered.