They are extremely dangerous to melee-oriented characters, as they are completely immune to physical attacks as well as some elements; this makes the very difficult if not impossible to defeat without the right spells on-hand. The easiest way to obliterate them is to use the Holy Word, assuming any party members have access to it. Luckily, they are not particularly powerful in terms of damage output, but unfortunately they have a creature ability that lets them permanently age foes, a process that can be difficult to reverse.