The entire first blood.

[mucuz]

So basically I have just got to the part of the story where you fight Tioman, and with her connection to Nidhogg it made me wonder - who are the entire first brood? Like I know Nidhogg is a main component of the first brood, along with his sister Tiamet, but has there been any others mentioned? It's fascinating and would be awesome to find out some more details, thanks