Something you do not need to see when you open tefillin: BUGS.
The vacated exoskeletons of bugs, I grant you (note the hole in the centre one where the bug burst its way out), but still, ick. At least a dozen of them.
Perhaps surprisingly, the klafim were ok, once I’d brushed the crumbled bugs out of the folds (ick).
I’m swapping out the batim, though. Ick.
Fortunately this was a donated set so I have no idea whose head was wearing all those bugs. Not something I would want to know.