The cross-shaped mark on a donkey’s back is a natural feature that many donkeys have, often referred to as a “cross” or “cross mark.” This marking is usually formed by the darker fur along the back, running in a cross-like shape, often extending down from the shoulders and across the spine.
One explanation for this marking is symbolic. Some people believe it resembles the cross that Jesus Christ rode upon during His journey into Jerusalem on a donkey. According to Christian tradition, this image is seen as a reminder of the humble way Christ entered the city before His crucifixion.
In reality, this cross mark is simply a natural variation in donkey fur patterns, but its symbolic meaning has made it a notable feature in both religious and cultural contexts.