Working Summon

I was wondering if there's a hacked client that can use summon, like spawning NPCs. TerraHax and other clients do not work and I don't know where else to turn.

Terrahax does work.. you just need the Right ID " .summon [NPC ID] [*Optional* Amount] "

for ex. Summon King Slime: .summon 50

It works but if you test it in multiplayer 2 windows open and use .summon on one and check on the other there is nothing there but the one who used .summon you can see it. So I want other people to see it not just me.

---------- Post added at 09:12 PM ---------- Previous post was at 09:03 PM ----------

I'm saying that you can summon things in multiplayer but it's not real. You spawn it you can see it etc but other players cannot see it or be touches by it. So that's what I am trying to say.