According to the debug mode this is known as the tower skeleton, and referred to as such in the programmer notes in 2000.msg. This character has his own unique texture in the files. If you climb the tower and enter into the battle with an invisibility potion, he can see through it, and will comment that the potion will not work. He will also comment if you try to use projectile weapons. Connor will put away his weapon and switch back to his hand weapon.