There it is, the entrance to the caves. Hungler was ready to dive in to possibly find out more about Ozzy and whatever the crash was, but Jacob decided to remain behind for some reason.
The Jellyshroom caves were extremely different from the grassy plateaus. They were full of purple mushrooms, minerals, weird Peepers and aggressive snake-like creatures that resided in the mushrooms. Hungler started to doubt whether he'd be able to find Ozzy or not, but he kept exploring anyways. The only real danger were the snake creatures which, thankfully, were blind and weren't much of a threat if you kept your distance.
Once he reached the deepest part of the cave system, he found a human base. He entered it, hoping to find anyone who survived. All he found, however, were voice recordings of the people that lived in this base. Most were about the three of them arguing with eachother, but there was one that sparked Hungler's interest:
"... but I stare out the window and sometimes I think how lucky I am to see this world up close. Back on the island I wouldn't have believed the creatures that live down here ..."
There is an island somewhere in this world which might help him find out more about these people.
The first (technically 2nd) Degasi seabase has been found and Hungler's next destination is now the floating island.