Wiktionary
vb. (en-third-person singularpony up)
Usage examples of "ponies up".
Since they could not run away and leave the little merchesti behind, they led the ponies up the western side of the hill behind them and stood their ground on the forested slope just above the campfire.
Meng and two of the other young men galloped their ponies up the rise.
The hobbits led their ponies up, winding round and round until they reached the top.
Two days after, tied upon his horse half lying down with a high fever upon him, he drove his ponies up to the fort, and was taken from the back of the animal nearer dead than alive, and most tenderly cared for by Major Van Dorn, who had returned only a short while before from his search for the brave boy.
They had just dismounted to lead their ponies up the last steep slope, when suddenly Frodo stopped.
She'd have preferred a gallop, or a flat-out run, but Dylan couldn't stay on Fimlas at that gait, and they couldn't use the ponies up now when they'd need them later.
Not if your family ponies up the ransom& Don't be a dizzard, Dunninger.