How about the one about the frog in boiling water?
This one, unlike the youth-as-generals, has a track record at lds.org (see here, here, and here for examples). It has even made it into the Gospel Doctrine teacher’s manual. (Although, admittedly, the wording in these references is usually more cautious than the youth-as-generals, using such phrases as “it is said that . . .”)
According to Snopes, it isn’t true.
Of course, I have no idea who Dr. Victor Hutchison is and whether he can be trusted.
Anyone have any frogs?