What do you call treating 2 monsters as one?
There's an old rpg trick me and my friends use which we call 'making a two headed snake'. The basic idea is you double a foes hp and give it two turns per round of combat. There's often a few other minor rules we apply for it based on the system but it's pretty simple.
Basically it's as if you have two of the same monster on the field challenge rating wise but they're combined into the one body. It's a fun way to make a dynamic foe that I feel like has been around for years.
We call it a two headed snake' because of an article that explained the idea very well done years back used a snake monster as it's example. But I've seen the trick called a dozen things over the years; hell I've seen it used as part of official rules such as fabula ultimas elites!
So I'm curious assuming your table knows of/ uses this truck what is you call it? Is there even a consistent name people use for this?
Edit:AS others have pointed out the two headed snake idea was come https://theangrygm.com/elemental-boogaloo/ in 2015. I had seen the method before then but he did a good job explaining it, codifying it, and spreading the idea. But I had forgotten name of the blog since then (It has been a decade~). Called it Paragon monsters at the time?