My own family is no different, with the kids starting to coin their own phrases that stick for better or worse. One of my favorites is "wild penguin." This term was originated solely by Rigdon and Livi. It was initially just the "Penguin." Then it evolved to "Angry Penguin" and is now "Wild Penguin." The official position of "Wild Penguin" is pictured below.
Recognizable when Caroline buries her chin in her chest with a slight look of distress, while avoiding eye contact and bowing her body as pictured above. When Sara or I hear Rig or Livi yelling "Wild Penguin!! Wild Penguin!!" It translates directly as "Get your 'mostly potty trained' daughter to a toilet ASAP!!" Thank goodness for older siblings.
(Fortunately this may have been the last we have seen of it, seeing that Caroline has gone by herself for the past 5 days.)