Merlin used the staff as a weapon, casting magic spells to aid King Arthur and protect Camelot. It eventually fell into the hands of Mordred after he was reincarnated as the seemingly humble school teacher, Mr. Moore. Eventually Merlin defeated Mordred by reclaiming the staff.
The staff is a wooden staff with a figure at the top. The figure changes depending on who is holding the staff. When under Mordred's control the staff was topped by a sinister looking dragon. When in Merlin's hands the dragon was replaced with a majestic lion.
At one point the staff looked like an ordinary wooden cane.