Philikkahn is an open species by the artist, km-15. The following furaffinity post shows a more in-depth description here:
https://www.furaffinity.net/view/38573240/

An excerpt from the furaffinity post:

Biology: Philikkahns come in all shapes, sizes, and colors, allowing them to adapt to a variety of conditions. Most of them take after their mother which is why a large number of their population is feminine. Most Philikkahns are quadruples, but some can be bipeds if they desire.
Philikkahns stop aging as they reach adulthood, making them immortal. The transition from infancy to adulthood normally lasts about a year. It is important to know that any wound received during this period will become a permanent scar when they turn adult.

Soul Gem: While Philikkahns can possess multiple gems on various parts of their body, their soul gem is always embedded on their chest. The soul gem is the life source of all Philikkahns and the crucial part of their species.