That is the aftermath of a big one (version 1.0.1)
items in hotbar are used for building it.
rightclick with one stabilized element while ontop of the dragon egg to get the unstable element
The mod adds some bombs.
it currently adds
pipe bombs
unstable elements
The "big one"
molotov
All things added have recipys
try putting the unstable element in a stonecutter
attempt to grill iron in a campfire
Mcreator is really cool!