St Anthony was alive in the high middle ages. So not a biblical figure. Much closer to the artists own time.

Edit: as below a more famous and earlier St Anthony was indeed much closer to the time of the gospels

There were two St. Anthony's. The one in this painting is the first St. Anthony. He was celebrated by Athanasius in a widely read biography and was famous for fighting off demons in the Egyptian desert. He lived from ~251-356 AD. (But yes, a post-Biblical figure.)