Whats that on rock

[txmk4]

Is that good or bad?

 

[WheatToast]

Do you have images under white light (ex. with a flashlight)?

 

[txmk4]

Do you have images under white light (ex. with a flashlight)?

Are these good enough?

 

[JGT]

Looks like a Zoa and a baby.

 

[WheatToast]

Looks like a coral in the Zoantharia order, which are very popular in the marine hobby.
https://www.saltyunderground.com/article/38-identifying-zoanthus-palythoa-and-protopalythoa

While Zoas do contain toxins, you have take them out of the water, have them squirt into your eyes, microwave them so they release fumes, eat them, cut yourself and have the toxin touch your wound, etc. for them to hurt you.

I have hundreds and maybe thousands of Zoas in my tank and no issues. I have a pet and my nieces and nephews came over to enjoy the tank often when they were little. Never had a problem.