Okay...what even...

[Hiachi20]

Can someone ID this please? Thank you very much for any help. There are a few of these around. In case it might be some sort of spawn, I have these:
Banded Tulip snail
Urchin
Sea hare
Nessarius snails
Conch snails (mating but probably not it)
Hermits
Turban snails
Decorator crab
Stone crab
Snowflake eel

 

[Jose Mayo]

Hydroids larvae

 

[KJ]

https://www.google.com/search?q=med...ved=0ahUKEwiFjPG8_NXNAhVD_WMKHeFzDUkQ_AUIBigB

 

[Hiachi20]

Thank you guys for the great IDs. So they seem to not be too harmful?

 

[KJ]

Thank you guys for the great IDs. So they seem to not be too harmful?

YW

 

[Jose Mayo]

Thank you guys for the great IDs. So they seem to not be too harmful?

Most of the time they are just a phase, in which they arise and disappear. When they settle in and thrive, especially if they do it in the midst of other corals, they can be a problem.

Regards