/kill @e[type=!player] or /kill @e[type=ender_dragon]

### I've searched existing issues and couldn't find a duplicate. - [x] I confirm this is not a duplicate. ### Is your feature request related to a problem? Please describe. Apparently, you cannot specify in commands, what entity you mean. I don't know how far this goes with missing command specification but it would be cool to have it. ### Describe the solution you'd like Add the command like in vanilla.