In the comics, he is a slightly aged looking gambling addicted businessman and his name is Thomas. He appears first during the Nerissa's return arc, and tries to repair his relationship with Will, who is quick to trust him; however Susan is distrustful towards the ex-husband. It is indeed quickly revealed that Tony is in need for money, and blackmails Susan threatening to take Will away from her if she won't pay him a very large sum: Will herself, eavesdropping the meeting between her parents, is left heartbroken.
During an encounter with Kadma, who surveilled Will for her whole life, the guardian is told that Tony was adept to high-risk investments which almost left their family on the verge of poverty, until Susan lost patience and hope and divorced from him.
In the end of the arc, Kadma herself pays him a very large sum, plus an extra in order "to never be seen again": Thomas gladly accepts and disappears from the series.
In the TV series, his name is changed in Tony: he divorced with Susan and disappeared for six months as said in "N is for Narcissist". His first appearance was in "M is for Mercy" as has red-burgundy hair. His relationship with Will is unstable, but undeniably better than the one in the comic. Tony also seems to not have the same financial troubles of his original incarnation, since he drives a luxury sports car and never mentions any debt.
Tony lives in an upper class condominium which is revealed to possess a pool, in which he invites Will to swim. "Q is for Quarry" reveals that Tony is engaged to a woman named Serena Sanchez, who is believed by a distrustful Will to be Nerissa. In the end, thanks to Blunk's investigation, Serena is revealed to just be a nice human and Will gives them her blessing for their relationship.