Hmm. I wonder if you should call this some variation "Skatt". Ignoring of course the unfortunate fact that then we have to call it "skattesystemet" and that kind of has another meaning...but it's not really an easter egg system. Drops are pretty common and well-documented. Nothing secret about them.

Another variation could be "etterlatt gjenstand" (tweaked according to the actual sentence of course). What do you think?