How to link objects

I asked this weeks ago and got an answer and went back to find it and it’s gone.

My alien model has about 15 different pieces to the body. How can I link all of them into one?

Create 1 object: select all and Ctrl+J to join.

or

Parent to main body: select all objects, main body as last one, and Ctrl+P

Just tried, did Join Meshes and the head still deattaches from the body and all.