Matthew 21:1 - 9 paints the following scene:
Now when they drew near Jerusalem, and came to Bethphage, at the Mount of Olives, then Jesus sent two disciples, saying to them, “Go into the village opposite you, and immediately you will find a donkey tied, and a colt with her. Loose them and bring them to Me. And if anyone says anything to you, you shall say, ‘The Lord has need of them,’ and immediately he will send them.” All this was done that it might be fulfilled which was spoken by the prophet, saying: “Tell the daughter of Zion, ‘Behold, your King is coming to you, lowly, and sitting on a donkey, a colt, the foal of a donkey.’ ” So the disciples went and did as Jesus commanded them. They brought the donkey and the colt, laid their clothes on them, and set Him on them. And a very great multitude spread their clothes on the road; others cut down branches from the trees and spread them on the road. Then the multitudes who went before and those who followed cried out, saying: “Hosanna to the Son of David! ‘Blessed is He who comes in the name of the Lord!’ Hosanna in the highest!”
Now consider the following;
Was Jesus riding one or both animals?
Do you know why this story appears at all in Matthew? It there a chance Matthew was simply setting the scene up so that it looked like the fulfillment of prophecy but was a bit careless with his facts?