Is this a Bad Paly?

[Retro Reefer]

can these release palytoxins that is very harmful and even deadly?

I love Retro threads the ones pictured in the OP’s original post look like green button Palythoa’s or Texas trash which are some of the most toxic paly’s, typically not a problem unless your handling them without gloves, trying to scrub them off rock or trying to boil the rock they are on.

 

[A. grandis]

can these release palytoxins that is very harmful and even deadly?

Yes, unfortunately they COULD.
Handle carefully!