Based on the intial version of his promotional poster, Gregor was possibly supposed to have the full name "Gregor Samsa" just like his book counterpart. However, due to changes later made to the design done to avoid potential copyright issues, it is unknown whether he still shares this last name as of the game's official release.
Gregor's callsign, "UNGEZIEFER" is the specific term Kafka uses to describe Gregor Samsa's appearance upon waking up in the opening sentence of the novella's original German text.
The term (alongside the entirety of the book's opening line) is famously known for having a wide multitude of varying English translations, with the English subtitles for Gregor's promo trailer translating the word as "hideous pest"
The associated book quote from his initial character teaser post on Twitter ("מטמורפוזה ungeheueren Ungeziefer")[1] is partially written in Hebrew (despite the novella being originally written in German) , likely as both a nod to Kafka's Czech Jewish family origins, and to distinguish him from Sinclair whose source novel Demian is also of Germanic origin
As seen above, Gregor's callsign was supposed to be "גרגור" (grgvr), the Hebrew transcription of his given name.
Due to accusations of plagiarism made by Jack Jung on Twitter over Yi Sang's original promo poster design — the promo posters which had been uploaded at that point (belonging Gregor, Rodion, Sinclair & Yi Sang) — were deleted and edited to remove the quotes derived from their source books to avoid potential copyright issues.
Gregor has a cockroach on his shoulder which is also present in almost all of his Identity art.
