Having wandered the world for time unknown and having been responsible for the destruction of innumerable island, it is often believed that Hastur is not a single being but a malevolent and eldritch force of nature named "The Terror in Yellow".
Personality And Relationships
Hastur has an extremely inhuman pesonality displaying no emotions or morals as such people see him as a terrifying force of nature rather then a being. He is incredibly intelligent having mastered all forms of science especially biology as he has an perfect knowledge of the biology of all living things which he is able to immitate. When conducting experiments Hastur always the same blank expression whether he is experimenting on a bug or on a sentient being as he sees them as the same. Despite his uncaring nature towards all mortal being Hastur has a seemingly strong loyalty for his captain as Belial seems to be the only being that he pays any heed to.
Abilities and Powers
Hastur has immense knowledge of all sciences both mechanical and natural as such he is personally responsible for the creation of the ghoul race as well as their weapons many of his own creation.
Hastur is the last remaing member of an ancient unknown race that has complete control of their biological make up which allows them to be functionally indestructible and mimic the abilities of any living being.
Hastur is an incredible master of Haki having trained in it for hundreds of years as such he has multiple unique abilities from it such as the ability to create weapons composed entirely of Haki and See into the future with ease.