I watch a lot of minecraft mod reviews, and sometimes, I see these npc type mobs/entities, and I don't know if it's a mod, or a server plugin thing, or what! The NPC/Mobs/Entities have green nametags, and if you right click on them (I'm just guessing this) there is a dialogue thing. They also seem to be invincible. Just copy and paste this link, go to 1:11, and you'll see the thing I'm talking about.
Here is the link->
Someone please tell me what mod it is! (If it is one, that is)
(And by the way, I didn't know where to put this, and it would be nice if I was told where on the forum I can put things like this, where I ask for help with mods. Thanks!!!)