Evil Beholders and Charm?

[ganjatron]

Evil Beholders have been a fixture in my army since level 7 (I'm 12 now) and in all that time, I have somehow charmed an enemy only twice. Usually when I use the "Mind Control" spell, I get the dialog to pick an enemy, then pick the target. However, during these instances, I was able to charm and control the enemy unit as if it were mine. One example was when I controlled a Werewolf Elf and was able to move it around and use its "howl" ability as if I were in full control. When I checked to see what spells were affecting it, "Charmed" was listed with an icon of little hearts.

Now, I'm assuming this was my Evil Beholder because the Werewolf Elf was the target of my mind control spell, but nowhere in its description do I see any reference to charming an opponent. Has anyone else experienced this? Anyone know what the probability you may charm an enemy is - and - is charm a spell you can get? Thanks.