Fire Giant Mental Weakness

Fire Giant page on the website says that they are weak to Mental in addition to their low Int/Wis. Score damage in game shows their only damage weakness to be Cold. Bash : Resistant 33% Pierce : Resistant 33% Slash : Resistant 33% Fire : Resistant 33% Cold : Vulnerable -33% Lightning : Normal Acid : Normal Poison : Normal Negative : Normal Holy : Normal Energy : Normal Mental : Normal Disease : Normal Drowning : Normal Light : Normal