Undead cript mod

i love how they added undead cripts and would like someone to make a mod that makes it so that on day 2 or 3. that would spawn in the world and it would keep spawning after you destroy it every 2 or 3 days. i no nothing about modding. i am going to go to collage for that. but right now, i would like someone to make it for everyone that would play this.

please repley if you can make this. =)