Freud se stal z malého doktůrka velký psychoanalytik.
The main verb is "stal se" 3sg. past tense form of stát se 'to become' and takes the instrumental case
The subject is the nominative form Freud.
z malého doktůrka is a prepositional phrase with the prepsotion "z" taking the genitive cas
What is missing is the X in the instrumental case in "Freud became X"