The special level loader would allow the level description to specify
an alternate monster appearance for any type of monster, and if one
was specified for a mimic then that mimic would be polymorphed into
the appearance instead of masquerading as it. This changes it to
only use an appearance for mimics, the Wizard, vampires, and general
shapeshifters (chameleons, doppelgangers, sandestins). The mimic
case doesn't work as expected: map display shows the symbol for the
specified shape but farlook describes it as a mimic. The Wizard case
hasn't been tested. The chameleon and vampshifter cases seem to work.
It also allowed shapechangers (including vampires) to be given an
object or furniture appearance. I didn't try things out to find out
what what their behavior would be if/when that happened.
I'm not sure whether the farlook issue for mimics-as-monsters is with
the pager code or the monster name formatting code. (Possibly the
mimic just needs to be flagged has 'hidden' as well has having an
alternate appearance.) I'm not going to worry about it since none of
our special levels attempt to give mimics a monster shape. Mimicking
a monster is a feature for clones of the Wizard, not for mimics,
although it might be nice if the latter worked correctly someday.