Raise its level
Why: the level raises all its stats and its army size. Note: capped by your campaign stage.
What helps directly
Map
Earn XP by hitting the right targets
Hit high-level beasts, wild dragons and knights: they give MUCH more XP than point defenders.
WhereWorld map
Keep in mind
Raise its level right now (meat)
Feed it meat to raise its level immediately. Note: meat disappears at the end of the season, use it before.
WhereFeed the dragon
Related bonuses (good to know)
Upgrades
Earn more XP each fight
In Upgrades, raise "Combat Training": your dragons earn more XP per battle.
WhereStronghold › War Tactics
Other needs · Make a dragon stronger