Subzero already sits on the most iconic of those lists, having won the 1992 Melbourne Cup, which for almost any horse would be enough, forever a seat at the top table.
But it is what Subzero did after he retired from the track that made him an icon and not a horse loved from afar or via television, but a horse loved up close by the thousands who actually touched him.
Teaming up with horseman Graham Salisbury, Subzero took horses and therefore racehorses into the lives of so many Victorians — be that their school or even their hospital ward.
He and Salisbury made children laugh and the gravely ill pause in calmness for a few precious seconds by visiting hundreds of venues as the greatest ambassador in Victorian racing.
At a time when racing's treatment of the equine heroes at the core of the industry has been questioned and protested again, Subzero reminded many people what is often lost in the industry squabbling and constant white noise of the machine driving the punt.
Horse racing still, at its core, centres on one of the most athletic and graceful animals ever born. Most of them love people and most of the people in the industry love them.
New Zealand racing alone may be a $1.6 billion industry, but to many people who go to the track, horses are a total mystery.
Subzero took away that mystery, and anybody who has spent real time around horses knows their benefits on the soul.
His death at 32, old for a horse, is not a tragedy.
It is the way of life, and when Salisbury passed away from cancer aged 76 in June, nobody expected Subzero to last the winter.
He was humanely put to sleep nearing heart failure on Saturday.
But this old gentleman of the turf, horse racing's Santa Claus, was a timely reminder of what horse racing is really about — the relationship between horse and human.
Ellerslie has seen many great horses cheered back to scale over the decades but the horses who truly touch the hearts most deeply there are often the clerk of the courses horses.
They stand guard at the entrance to the parade ring and will accept the most tentative of pats from occasional racegoers fascinated by being so close to a horse.
Subzero took that thrill, that moment of serenity, to those who needed it most.
He might not have been Australia's greatest thoroughbred. But he was perhaps the most precious.