Use the call script event command and put this into it:
$scene = Scene_Bestiary.new
This will call the Bestiary. If you want to add only "analyzed" monsters to the Bestiary, you need to change a value in the configuration. I haven't taken a look at those scripts for quite some time, so I can't remember exactly which one, but I've typed it down in the instructions of the Bestiary, so you should be able to find it easily.
Change these lines:
self.contents.draw_text(x_offset, 32, 256, 32, _HP)
self.contents.draw_text(x_offset, 64, 256, 32, _SP)
to these:
self.contents.draw_text(x_offset, 32, 256, 32, "???")
self.contents.draw_text(x_offset, 64, 256, 32, "???")
Then change
self.contents.draw_text(x_offset, 32, 256, 32, _HP)
self.contents.draw_text(x_offset, 64, 256, 32, _SP)
to this instead:
if [ID1, ID2, ID3].include?(enemy.id)
self.contents.draw_text(x_offset, 32, 256, 32, "???")
self.contents.draw_text(x_offset, 64, 256, 32, "???")
else
self.contents.draw_text(x_offset, 32, 256, 32, _HP)
self.contents.draw_text(x_offset, 64, 256, 32, _SP)
end
In the array [ID1, ID2, ID3] include all enemy IDs (separate them with commas) which will have ??? instead of the values.