Eggs found by Toothless on a search need to be hatched in the Hatchery before the dragon can be placed, only one egg can be hatched at the Hatchery at a time.
Premium purchase options to hatch up to three eggs at the same time are available.
This building can only be upgraded via Premium Upgrades.
A second hatchery spot can be opened by purchasing a premium upgrade for 150 Runes.
A third hatchery spot can be opened by purchasing a premium upgrade for 1,000 Runes.
Premium purchases are instant and permanent.