If you already watched the new Evolve story trailer then you most likely saw the third monster. Cabot goes on to talk about the monsters, he explains Goliath and kraken and then says " but those are only the ones we know about " then the trailer shows some giant alien creature trapped in a water enclosed cylinder. Also later in the trailer one of the assault characters gets upper cutted by and unknown specimen that fits the description. If this is the third monster I’m pretty pleased because he/she looks badass! She seems to play fast and agile which I was hoping for! If you haven’t seen the trailer then go watch it now!
Yup, it’s pretty much confirmed that the 3rd monster was in that section of trailer. That being said, there is a huge discussion on the trailer in the New Footage thread.
Cool thanks for letting me know!