What does frivolity mean? - Nathan Drake

I have been scouring the internet for "artifacts".  Well, let me backtrack a bit...

I know I said I never wanted to be a parent, but that doesn't mean I don't love kids.  In fact I have a big squishy spot for my nephews and nieces.  For the past year and a half their lives have revolved around the treasure hunter video game Uncharted.  They model themselves after the main character, Drake and walk around in their Drake swag any chance they are given.  They have leather bound journals that they fill with sketches of their treasures.  When they aren't playing the video game they are skulking around the house playing "Drake" and getting into true Indiana Jones-Style trouble.  The two older boys have encouraged their five year old sister to join in the mix.  Their mother, my sister, reported to me that the other day her daughter came down the stairs, her arm wrapped in an ace bandage.  When my sister asked what happened, my niece reported "A drunk guy knifed me!" And when my sister looked upon her daughter incredulously, her older brother said seriously "Treasure hunting is a dirty business mom."

So this holiday season I am attempting to outdo my former attempts.  Previous birthdays I have given replica terra cotta warriors, money from all around the globe, treasure chests emblazoned with ancient family crests and books about every history and archaeology they find themselves interested in.  I was thinking some replica canopic jars, or maybe a carved sculpture of the Mesoamerican deity Quetzalcoatl (Pronounced Ketzle-co-atl, as in Dr. Ketzle-co-atl.  Sorry sir, I couldn't resist.)

Calling all ideas!