Crackshot + java?

Hello before i start, i wanna say that i'm not a pro or starter for java, i do not know anything about coding or else, i was just curios if someone could help me with this

okay so, there is a gun on a server called CosmicCraft, the gun name is Nixys Relativity Rifle, it acts like a black hole, it sucks entities into it, and the gun can fire mobs really high into air, with a high speed, (like a rocket for example), my friend told me that it uses java and something called Spawn_Skull: -2, can someone exaplain please how do i make that, work

 

@TheHomingPig
Well in all honesty, I would go learn java first.
Do not start with Bukkit/Spigot, it can be challenging. Especially because you said that you do not know anything about coding.
BUT, your friend most likely uses an item, and a texture pack to create the gun, and then he probably spawns a wither skull and shoots it at the entities, which then he sucks them towards him and increases the entities Y value once they are near him, resulting in them being shot up in the air.

 

@TheHomingPig

In that case, you should not be the one making this plugin. You need to know how to write in Java before you can make bukkit plugins. I would recommend either learning Java first before creating this plugin, or ask in the PluginRequests forums for this plugin to be made for you.