PASADENA, Calif. — With his frizzy hair pulled into forward-protruding spikes and his goggle-size glasses, Max Pauson resembles one of the futuristic comic-book characters he admires and draws. Ebullient and eager to show a sketchbook filled with startling portraits, he seems to have identity to spare.

But this promising art student’s strong sense of self was hard-earned. It was forged in an unstable, emotionally wrenching childhood and, in an odd detail that might serve as a metaphor for his struggles, it comes after 19 years of life without a legal name.

His birth certificate read only “(baby boy) Pauson.” Name to come.

His father had disappeared. His mother — in his words, “a pack rat who takes a really long time to decide on anything” — did not pick a first name at the hospital in San Francisco in 1990. And she never followed up, leaving him in a rare and strange limbo.

While Mr. Pauson was long aware of the blank spot in his identity, he never quite had the time or means to correct it. He lived with his mother in a house that sometimes lacked electricity. He spent time in foster care and returned to live with his mother in homeless shelters and in public housing. Finally, at 15, he ran away to live with friends’ families.