[HELP]Creating your own mobspawn?

[Kalayci]

Hello everyone :)

Some of the players on my server were asking if I could put a mob spawn outside of junon
So I decided that I was going to put an Astarot King spawn there, but when I try the /SSPAWN and /SET command nothing happens, maybe I'm forgetting something?
I'm using rev 41 btw.

Could you guys help me with this?

[MentaL]