The image is unsettling. Jacob compares Dan to a serpent lurking beside the road, waiting for horses' heels. Targum Pseudo-Jonathan explains the metaphor and names the man. "A chosen man shall arise from the house of Dan, like the basilisk which lieth at the dividing of the way... Even thus will Shimshon bar Manovach slay all the heroes of Philistia" (Genesis 49:17).
Samson, the Targum says, fought the way a snake strikes. He did not lead armies. He did not array troops. He ambushed. He wrestled jaws off lions, pulled temples down on Philistine lords, and undid whole military campaigns alone. The Aramaic notes that he would "hamstring their horses and hurl their riders backwards" — guerrilla tactics, not phalanx warfare.
Why a serpent? The rabbis note that a serpent is small, overlooked, underestimated. Samson was one man against the organized armies of five Philistine city-states. Like the serpent, he picked the moment and struck where the armor ended. The horses fell. The riders flew. Israel breathed for another forty years. Jacob, staring at Dan on his deathbed, was already watching it happen centuries ahead of time.