Yeah, I figured it could be those, though it's interesting that BioWare seems to be giving them a brand new title. I suppose this is how people will start calling them, I suppose they could be a lot more present rather than a force working behind the scenes like Corypheus.
This does look like something that could be from the Horrors of Hormak, though Dragon Age does have
giant sea creatures, so it could be something like that too (or maybe the giant sea creatures
are creations from Ghilan'nain, who knows at this point lol). Either way, I'm so happy to see this. Slaying dragons in Inquisition was one of its best parts, so I'd love to have some optional monsters to slay in the next game as well.
Seems to be a trend with BioWare games now too, as ME Andromeda also had the Architects.
EDIT: Yeah, giant sea creatures are her creations, indeed:
So... Pride - with a capital P - stopped her hand. I guess Solas is going to use them as weapons?