Is there anything particularly special about the weapon Moshe used against Og? The Gemara Brachos (54b) records
משה כמה הוה עשר אמות שקיל נרגא בר עשר אמין שוור עשר אמין ומחייה בקרסוליה וקטליה.
The story concludes: How tall was Moses? He was ten cubits tall. He took an ax ten cubits long, jumped up ten cubits, and struck Og in the ankle and killed him.
(Based on the years of experiences with the staff, I expected Moshe to use the miraculous matteh to finish off Og - as the Me'am Loez Haggada (p.69) quotes the Zohar Chadash, Beshalach saying the "staff was under Moshe's authority until the Mishkan was erected....he could take it anytime he needed it to perform a miracle." Taking on Og would seem to be one of those miracles.)