While Sol was able to hear a voice from the inner body of the serpent, what Gin heard from the boar was a heartbeat.
Now that he thought about it, that must have been due to the fact that he was a werewolf. Like a real beast with high, keen senses, he could easily detect people's footsteps and heartbeats, loud and clear. It wasn't just his form that changed, but also his ability increasing when it came to such things related to senses in and outside his body.
There was a large mist that surrounded the serpent they were facing. Gin realized this serpent was indeed different from the one he and Sol had encountered back in Teserus Forest and also from that exotic lake in the outer wall forest.
