Calidoscopio (foaled September 10, 2003) is a retired Argentinean racehorse who is best known for his victories in the Breeders' Cup Marathon, and the Brooklyn Handicap.
He was bred by Haras La Quebrada and during his racing career was owned by Dona Pancha Stud.
He did not win another race until his six-year-old season, in the Grade 1 Republica Argentina in 2009, although he didn't cross the wire first.
He overcame mild interference again in his next victory, the Grade 2 Clásico General Pueyrredon, as he navigated between multiple horses from the back.
After he was clear in second place, leader Best Guest veered from the outside to the rail, and Calidoscopio made a small check-up.
His final race in Argentina was the Grade 2 Clásico General Belgrano, where he went to the far outside and won with a length to spare.
Calidoscopio dropped as far as 20 1/4[2] lengths behind the leaders as Belmont Stakes third-place finisher and Marathon favorite Atigun was in the lead.
Sense Of Purpose and Fame And Glory pulled up out of the race as Calidoscopio slowly began to accelerate going down the backstretch for the second time.
The first was the Tokyo City Cup Stakes, a race he was nearly scratched from due to cutting one of his front hooves.
Gryder later said that he "wasn't 100%.” In the Brooklyn Handicap, his main competition was Percussion, who led from nearly start to finish , and Ruler On Ice, the winner of the Belmont Stakes two years earlier.
He ran down Percussion, who had a three-length lead at the top of the stretch, to win by a length, and became the oldest winner of the Brooklyn, beating out the previous record-holder, Borrow, by a year.