He has short and wavy black hair, and pale blue eyes with pale skin. He usually wears simple, pattern-less clothes with one basic color.
Though he is very smart and the family is implied to get a majority of their wealth from Augustine's research reports, he puts his daughter's safety and happiness over all else in his life, even if it means risking his own safety and/or happiness along the way. Though he has held this belief ever since Madeline was first born, this has only increased ever since her ability to alter timelines was discovered.
When Madeline first discovered her ability to warp timelines through her severe fever, it also was made known to Augustine that he would become her Warp Link: the person who she would always re-encounter as she traveled through every timeline. Though it did not become particularly important until they began to travel together, he has begun to purchase lavish residences in every location that they travel through, in order to give her a signal that he was there with her.
He was also noted that due to the strange time flow surrounding the two of them, they have been given eternal life; However, he has yet to tell her this.
Madeline Sycamore: His daughter, he loves her more than anything, and would give his life if it meant keeping her safe and secure. There are still secrets about her timeline-jumping abilities that he is keeping from her, though he insists to himself that he's doing this to keep her safe from harm.