Sorry, not I understood.
What exactly do you want to be informed in command "nl"? List of monsters!?
If you could talk to the simplest English possible. My English sucks, I'm using Google Translator.
The current information you can see when you type "nl" is:
# Name Coordinates ID
0 Test NPC (X, Y) 10000
To make it more informative maybe we can add another column that will display if the NPC is using a monster sprite or a monster look.
# Name Coordinates ID Misc Info
0 Test NPC (X, Y) 10000 I look like Poring