Limited support
This feature is only present in Portal 2: Community Edition and Portal: Revolution.

npc_select

🟩 Executable on Server

npc_select

Select or deselects the given NPC(s) for later manipulation. Selected NPC's are shown surrounded by a red translucent box Arguments: {entity_name} / {class_name} / no argument picks what player is looking at

Warning:

This is a cheat command and can only be used when sv_cheats is set to 1.