Create modified version of a monster replicating across all instances

I just started having difficulty modifying just one instance of a monster without having it replicate across all instances of that monster.  I found this older forum post that no longer accepts replies and it's not working.  I just did this a couple of days ago and it worked so I'm not sure why it's not working right now.  There is a current issue with the Roll20 Compendium.  Could this be affecting it?  Here are the instructions I'm following. * Drag the monster you want to modify onto the VT, which adds the monster sheet to your journal.  * Click the monster name in your journal to bring up the monster info window.  * Click "Edit" button * In the Edit window, click on the "Duplicate" button, which puts a copy of the monster into your journal. * Edit the copy as needed. 

You haven't said where the process is breaking down, but I'll make a suggestion for a step not included in that process. You need to open the token, and associate it with the new character. When you duplicate a character, you duplicate the default token, every setting, including its association. If duplicate a goblin and change it to a nilbog, the default token does not change, it still points to the original goblin. You need to place an instance of the token, open it, associate it with the nilbog and then save it as the default token of the nilbog. Otherwise, every time you pull a "nilbog" from your journal, you will get a "goblin" token.

Thank you for your reply Keith!  I'll be more specific with what I'm trying to do. First, this was helpful because I have two veterans (5e D&D) chasing some Greater Zombies.  For the veterans I created two new tokens and under token represents I chose Veteran.  Now, when I click on the token while holding shift I can quickly access the character sheet.  However, I've found that if I use this character sheet to make attacks the chat log will show the name veteran.  So, went into the character  sheet and used the gear cog in the top right to open NPC Options and change the name so now it will show the name I made up and not veteran in the chat log.  However, the default veteran was not changed by this. Now, I want to change the name of the zombies the characters are seeing to Renegade Zombie.  I can change the token name and make the name visible to the characters on the token and that's what they'll see.  However, when I open the character sheet and use it to make attack rolls Greater Zombie will be displayed in the chat window.  If I open up NPC options in the character sheet and change the name there it changes it for all Greater Zombies everywhere.  I don't want this Also, I'd prefer to use the standard zombie token that the characters are use to seeing so they won't be immediately tipped off that something is different here.  Based on what you're saying I think the reason I was able to do this the first time was I was using a custom made token.  Now, is there a way to do this with the default zombie token that's points to Greater Zombie?  If I make the token generic/none then I lost the ability to open the character sheet from the token.  I want to change the 7 greater zombies on the map to have their character sheet name be renegade zombie without it changing the default greater zombie character sheet.  Is there a way to do this using the default zombie token that is pre-loaded into the adventure?

The very simplest thing to do would be to turn off this setting: Then no name at all will be displayed with the attack. If you want it to display something in that field in chat, but want to change what it displays, change the name using the NPC settings gear icon. The template pulls from the npc_name attribute, not the name of the character journal itself. What you might be running into is changing the name but still using the default token. When duplicating a character, the default token associated with it points to the original character, not the copy. It's counterintuitive, but it has to do with how the token is stored.  You have to associate the default token with the new character sheet. So after duplicating and making changes to character name, token name etc, put the sheet into edit mode, delete the old default token and select the new, edited one as the new default. It will then point to the correct sheet when you pull copies onto the VTT.

Yes, I want to display the name in the attacks.  It's finally working.  thank you for all of your help!