What are these cool flower looking things

[POLARBEAR0871]

This is the same rock with the sponge type thing on it. This rock also has these flower looking things on it I like them because they're pretty but idk if they're bad or not here's a picture

 

[bribo12]

Zoanthids or palythoas

 

[POLARBEAR0871]

Are they bad or do they benefit the tank because i really like them but they've spread rapidly across the rock

 

[SamB38]

They are pretty harmless from what I understand. Zoas contain a toxin to humans (Palytoxin) but as long as you don't go eating it or handling it to much, you don't have anything to worry about. I would just let it be, and enjoy!

 

[POLARBEAR0871]

Sweet thanks for your help they mind boggling me at first since I'm a newbie at salt water aquariums