Monster arena
From Grimhaven Wiki
The monster arena is where you hatch your Monster Eggs.
You can gain access there through a teleport located in Thais depot.
When first entering the teleport you will find two arenas, one to the right and one to the left
these are public arenas and anyone can enter. If you head south you will find private arenas wich you
can rent for 30 minutes with the cost of 5 Grimhaven Tokens for you and your party members.
You can also find the weekly boss Scorchwing in the monster arena, through a teleport to the south west.