"Steal The Cub" 

So...the cub they wanted to steal was an egg, or the one that already came out of the egg? 

Everyone basically thought that this place belonged to the mysterious monster and everyone also tacitly believed that the mysterious monster must be some kind of Loch Ness monster. 

And so, everyone had a 'new direction' to explore, but there were still too many mysteries that they could not answer. 

"No matter if this place belongs to the mysterious monster, at least, we must have arrived at a lair or a nest." 

The mermaid affirmed this conjecture because this place really did look like a lair with many 'personal items' of monsters or beasts such as a large shell bed, a rock chair, and so on. 

These items were all not as exquisite as the human's furniture and it looked extremely rough, but judging from the shape, these rocks, corals and many natural resources were all shaped to accommodate certain needs!