“Destroying enemy buildings with his massive cannon is his job; making a raggedy blond beard look good is his passion.”
The Royal Giant card is unlocked from the Royal Arena (Arena 7). He is a building targeting, medium-ranged troop with high hitpoints and moderately high damage. A Royal Giant costs 6 Elixir to deploy. His appearance is similar to that of a Giant but he sports a darker colored cloth coat, has a moustache with sideburns which go down to his chin, wears an earring on his right ear, and wields a cannon in one hand and a cannonball in the other.
Since the Royal Giant is a ranged troop, he will not protect any melee or short-range troops from enemy defenders, making his high hitpoints worthless as a meat shield.
However, it is possible to use the Royal Giant as a tank if the player puts down melee troops after the Princess Tower targets the Royal Giant.
The Princess or the Magic Archer can stay safely behind the Royal Giant since they have a longer range than him. Keep in mind that spells such as The Log and certain troops can nullify this synergy.
The Minion Horde, Skeleton Army, and Barbarians can effectively counter a Royal Giant due to their high damage output, minimizing the amount of damage the Royal Giant is able to do. However, they are defeated easily by supporting splash units like the Wizard or spells like Arrows.
The Ice Wizard's ability to slow down troops can also be an effective support option to make the Royal Giant less of a threat.
The Inferno Tower is one of the best counters since it distracts the Royal Giant while taking it down quickly. However, beware of spells such as Zap or Lightning as they can be quickly deployed to reset the ramp-up damage.
Even if the opponent lacks an Inferno card, Lightning is useful to support a Royal Giant as he will often force more than one card out of the opponent's hand, allowing the spell to gain positive Elixir trades.
Royal Giant synergizes well with the Furnace. The Royal Giant's range makes him stay close to the bridge, allowing the Fire Spirits to reach him more quickly and deny any swarms the opponent tries to deploy on top of him.
Placing him on the end of the bridge allows him to attack the enemy Princess Tower after taking just a few steps, making him a pressing threat. After destroying one tower and opening the lane, he can be placed in the middle of the opponent's map to almost immediately attack the second Princess Tower.
If the player fails to place a building on time and an opposing Royal Giant locks on to the Crown Tower, they can use a stunning card to cause the Royal Giant to re-target and hit a placed building instead. If none of these cards are available, the player can also slightly shove the Royal Giant by placing troops or buildings on him, which also forces a retarget.
On 23/3/16, a Balance Update increased the Royal Giant's damage by 20%.
On 3/5/16, the May 2016 Update increased the Royal Giant's range by 1 and also changed his description. It used to say, "Sighting his massive cannon at enemy buildings, the Royal Giant comes in like a wrecking ball." The same update also fixed the "range bug" and decreased the range by 0.5 tiles with no change to effective range, thereby providing a 0.5 tile increase (effectively a 1 tile increase in range).
On 18/5/16, a Balance Update decreased the Royal Giant's damage by 4%.
On 24/8/16, a Balance Update decreased the Royal Giant's hit speed to 1.7 sec (from 1.5 sec).
On 19/4/17, a Balance Update increased the Royal Giant's deploy time to 2 sec (from 1 sec).
On 1/10/18, a Balance Update decreased the Royal Giant's range to 5 (from 6.5), but increased his damage by 60% and decreased the deploy time to 1 sec (from 2 sec).
The Cannon he wields appears to be a turret of a level 7 Cannon from Clash of Clans. When it is Star Level 2 or above, this turret takes the appearance of a level 10 Cannon from Clash of Clans.
Oddly, the cannonball he holds is larger than the cannonball fired from his Cannon. Even so, the Royal Giant can be seen loading this cannonball back into the cannon during the recoil animation after he fires.
The Royal Giant's damage per hit is 10% of his hitpoints.