Is it legal to sell games based on Siren Head ?

With all the Siren Head games coming out lately, I'm wondering if it's legal to sell such games or does the original creator of the Siren Head character hold the rights to the idea? Most of the games are free, but I think some allow people to choose whether to pay a voluntary amount of money.

 

You would need the permission of the author (Trevor Henderson).

 

You can not sell them without working out something with Henderson, as Ryiah said (twitter: https://twitter.com/slimyswampghost), but he's stated in the past that he's okay with free games as long as he's properly credited.

 

As far as I know, the very idea of the siren head is not copyrighted. Games and films that are based on the siren head stories are usually copyrighted. I can advise you Siren Head Retribution developer interview maybe after reading it you will find out the answers to your questions. I could not finish reading it to the end, as I stopped at a video about this game. Then YouTube recommended me similar videos and in the end I spent about four hours watching all of this. I especially liked the video, which said that the siren head is the embodiment of all the fears and horrors that were during the second world war. Of course, there are many more myths, but we all know that in fact this is just a fantasy of an American artist who has been interested in horror films since childhood.