Targum su Esodo 7:9

When Pharoh talketh with you, saying, Give us a miracle, thou shalt say to Aharon, Take thy rod, and cast it down before Pharoh, and it shall become a basilisk-serpent; for all the inhabiters of the earth shall hear the voice of the shriek of Mizraim when I shatter them, as all the creatures heard the shriek of the serpent when made naked at the beginning.

And throw down before Pharoh.