These mugs were available to the Highlander Fan Club.  (I was a member for years! I even went to The Gathering convention in Anaheim and got to see the entire cast including Roger Daltrey singing with the Jim Byrnes Band)

This is an un-signed mug of Adrian Paul as Duncan Macleod.  It is about 6 1/2 inches tall.  Ceramic.  I don't find any defects or chips.  See pictures.

If you look closely, the handle is his famous Katana.