Exodus 7:8-13 gives Moses' first meeting with Pharaoh and his magicians.

........................The first sign was Moses casting down his rod which instantly turned into a snake.

"Aaron cast down his rod before Paraoh and before his servants and it became a serpent.

Then Pharaoh also call the wise men and the sorcerers; now the magicians of Egypt, they did also in like manner with their enchantments. For they cast down every man his rod and they became serpents, but Aaron's rod swallowed up their rods" Exodus 7:10-12