@Jacobm001 Hmm -- I think they both allow you to gasp arbitrarily attach members to an object (saving the hassle of minor subclassing/composing) but in addition perl won't tell you there's anything wrong with referring to a non-existent member because of a typo. It's just considered undef. Bury that in an obscure, untested path in a few dozen classes spread over thousands of lines and voila the stealer of souls.