3Clash Royale card guide
Cannon is a cheap, sturdy defensive building. It pulls ground troops, especially building-targeting cards, and protects your towers.
Place Cannon in the middle of the lane, close to between your two towers; Hog Rider, Giant, Royal Hogs and similar cards turn to it while your towers shoot them. In fast cycle decks it's the cheapest way to defend Hog Rider.
Cards that deal with it efficiently:

This card has an evolution. The evolution is active in your deck’s 1st (Evolution) or 3rd (Wild) slot. The Evolution slot unlocks at Arena 3, the Wild slot at Arena 10.
ElixirDeck automatically takes your unlocked evolutions and heroes into account: build your decks.