One of the first things you’ll need to do in The Eternal Cylinder is hatch an egg. Far from what you’d expect to be doing in this game, it’s not entirely clear how you heat the egg to get the Trebhum inside to hatch. This guide explains how you heat the egg and cause it to hatch.
How to heat up the Trebhum egg
Once you’ve picked up the Trebhum egg, you’d be right in thinking that you need to look around for a heat source to warm it. There are two very close by, the large structures emitting a warm red glow that seems to be steaming at the top. You need to place the Trebhum egg inside one of these structures and wait for it to glow red, wobble, and finally hatch.
The Trebhum that emerges from within the egg will be immune to the heat of the structure the egg was placed in, so don’t worry about it burning alive. This Trebhum will now join you on your journey across the world as you try to evade The Eternal Cylinder and cross vast lands in the process. Any evolutionary changes you make to your Trebhum will also be applied to your new partner.