The Xilians were as race of humanoid aliens that lived on Planet X and were the original creators of Monster X, their species went extinct during The Thousand Year War .
Appearance
In terms of their outer appearance of human beings. However the human like appearance is merely an outer shell as on the inside of this skin is a humanoid form that is thin and has black and silver coloured flesh, this form lacks eyes and in place of eyes are black veins.
History
The Xilians inhabited their home world of Planet X but soon they were involved with a great war with many other alien races known as The Thousand Year War. In the war the Xilians joined forces with the Nebulans and the Devonians against the Kilaaks, Simians and Millennians. In order to combat their enemy, the Xilians created Monster X by combining their own DNA with that of King Ghidorah's species.
At some point in the war, the Xillians sent Monster X to help the Devonians who were being invaded by the Kilaak and their Kaiju Hedorah, the battle resulting in the destruction of the Devonian home world. When the war ended, the Xilians along with the other races are wiped out as a result of their battles and as a resulted, Monster X is freed from their control.
Abilities
Advanced Technology: The Xilians possessed advance technology such as advanced weapons, space craft and advanced bio-engineering which allowed them to create Monster X.