Once you have acquired a
dragon forge core, a dragon
forge input, 8 dragon bone
blocks, and 17 dragon forge
bricks, you can construct the
dragon forge itself.

In order to power the forge,
dragon's breath is required.

This can be achieved by placing
a tame dragon directly in front
of the input. The dragon will
begin to breathe into the input
as long as there are valid items
in the forge.