The individual designated Android 20 in the Dragon Ball franchise is, in fact, Dr. Gero himself. He transferred his consciousness into an android body to achieve immortality and continue his quest for revenge against Goku. This transformation effectively made him a cyborg, retaining his original mind within a mechanical form.
This particular character is significant within the narrative due to his role as the primary antagonist in the Android Saga. His scientific genius allowed him to create powerful androids, including Androids 17 and 18, who posed a significant threat to Earth. The character’s backstory and motivations provide a crucial understanding of the events unfolding in the saga.