Dr. FRANXX

Dr. FRANXX (フランクス博士) is the old man responsible in constructing FRANXX.

Appearance
He has the appearance of an older man, sporting grey hair and a mustache. He normally wears a white coat similar to the other adults in the setting, along with white gloves, and uses a cane. Half his face and several digits of his hand are mechanical.

He has a horned mask implying that he may also have been a klaxo-human like Zero Two.

Personality
He has the nature of a calm individual, with a lecherous streak as shown when he groped Nana. He takes pride in his creations, but does seem rather disinterested in the formal procedures, such as when he was asked to attend the ceremony.

History
He appears in Episode 1, escorting Zero Two along with the cargo needed for testing that he intends to carry out at the Thirteenth Plantation. When the Mohorovic-class Klaxosaur appeared, he observed it before Strelizia dispatched it.

Relationships
The doctor seems to have an almost parental relationship with Zero Two, given the tone he speaks to her with and how casually he accepts her behavior.