Yes and no, maybe.

Originally, there wasn't, as Trigon is not a demon-demon, just a demon-like entiry from a pocket dimension or something.

However, in the New 52, one of the Sons of Trigon is Belial, which is the name of an actual demon - which has been used as the father of Etrigan before. Whether the Son of Trigon Belial is the Demon Belial is up for debate.

K thx

Belial is that Belial. There was a rebirth series with Etrigan where he fights against Belial and kills him again. Belial here has his NE appearance but Etrigan faces off against his uncles before who were the same ones from N52, confirming that they are supposed to be related. To make things weirder for everyone, Merlin and Etrigan are half brothers or something now.

They always were brothers IIRC.

So like why doesn't Merlin have horns anyway?

They're half brothers.

Right. But is Belial somehow able to use Trigons spell and possess a man to use? Even then, Raven has that other form while we haven't seen such a thing for Merlin.

Totally, ones a rhyming demon and one isn’t.